In order to explore the influence of dryland conversion to paddy field (dryland-to-paddy) on soil aggregate in southern red soil area, traditional dryland (HS0), dryland conversion paddy field 1 year (HS1), dryland conversion paddy field 5 year (HS5) and local traditional paddy field (CK) were selected in typical dryland-to-paddy area of Guangxi, and dry and wet screening method were used to analyze the soil aggregate properties in the tillage layer. The results showed that the contents of soil aggregates >0.25 mm (R_>0.25) in mechanical aggregates and water-stable aggregates under HS0, HS1, HS5 and CK treatments were 90.0%, 94%, 95.8%, 98.1% and 81.0%, 70.6%, 76.0% and 95.4%, respectively; the mean weight diameter (MWD) was 3.35, 3.63, 3.69, 4.73 and 2.25, 0.94, 1.54, 4.63, respectively. Compared with HS0, the geometric mean diameter (GMD) of the water-stable aggregates treated with HS1 decreased by 68%. Compared with HS0, the percentage of aggregate destruction (PAD) of > 0.25mm aggregate increased first and then decreased with the years of dryling-to-paddy field, HS1 and HS5 increased by 61% and 34%, respectively, while CK significantly decreased by 76%. The results of structural equation model and random forest analysis showed that soil cation exchange capacity (CEC) and total nitrogen (TN) were important factors affecting soil aggregate stability in dryland-to-paddy field.