Abstract: Under the background of urbanization development, cultivated land fragmentation has become one of the key problems restricting agricultural modernization and large-scale development, which seriously threatens the security of food production in China. Combined with landscape pattern index method, comprehensive index method, entropy method and Pearson correlation coefficient test, a comprehensive evaluation model of cultivated land fragmentation was constructed to evaluate the spatio-temporal evolution of cultivated land fragmentation at district and county scale in Guangdong Province. On this basis, combined with the land use transfer matrix, the characteristics of the dynamic transformation of cultivated land in Guangdong Province were analyzed, and the main influencing mechanism of the landscape fragmentation of cultivated land was identified by variance expansion coefficient test and geographic detector. The results showed as follows : 1) From the perspective of time, the change trend of cultivated land fragmentation in Guangdong Province was as follows: slight decrease - continuous increase - rapid decrease, and the time fluctuation of fragmentation was large. From the spatial perspective, the high value of cultivated land fragmentation index is concentrated in the west of Guangdong, the low value is concentrated in the north of Guangdong, the west of Guangdong has the largest change, the north of Guangdong has the smallest change, and the spatial distribution difference of fragmentation is large. With the change of time, the degree of fragmentation gradually showed a radial distribution from the Pearl River Delta to the periphery, and the high value of fragmentation shifted from the west and east of Guangdong to the Pearl River Delta. 2) The evolution of cultivated land fragmentation is significantly affected by nine factors, including total output value of agriculture, forestry, animal husbandry and fishery, urbanization rate, GDP, altitude, slope, average annual precipitation, population core density, distance from residential areas and distance from roads. Among them, socio-economic factors such as total output value of agriculture, forestry, animal husbandry and fishery, urbanization rate and GDP play a leading role in influencing the fragmentation of cultivated land landscape in Guangdong Province Output value is the most important factor. This shows that socio-economic factors are the main factors to curb the fragmentation of cultivated land in Guangdong Province, and become an important factor affecting the fragmentation degree of cultivated land in this region. 3) The evolution of cultivated land landscape fragmentation in Guangdong Province has four typical driving mechanisms: First, Yunan County is represented by the project of returning farmland to forest, and the fragmented cultivated land patches distributed in hills and other areas are reduced, which makes the distribution of cultivated land tend to be concentrated; Second, Gaozhou City is the representative of the improvement of farmland protection related policy intervention to alleviate the degree of farmland fragmentation; The third is Yangxi County as the representative, the adjustment of crop cultivation type and the change of land use type lead to the reduction of cultivated land area; Fourth, Huangpu District as the representative, the change of industrial structure and social and economic development led to insufficient attention to the protection of cultivated land.