The invention discloses a rice field fish culture fish ditch digging method, and particularly relates to the field of ecologic aquaculture. The method comprises the steps of measuring, selecting a site, digging, manufacturing a fish ditch, sterilizing, manufacturing a stop net, performing precuring of fish fry and migrating the fish fry. By manufacturing a ditch wall and a fixing ring, the dug groove contour is protected, the secondary digging requirement caused by deformation of the groove and collapse backfilling is avoided, the service life of a fish tank is ensured, the slope inclination ratio of the shape of the groove can be ensured, the fixing ring is adopted as a fixing point of a fish blocking mesh, a user can fix the fish blocking mesh conveniently, the phenomenon that the fish blocking mesh is directly fixed to soil and looseness is caused is avoided, and therefore the service life of the device is further ensured. Due to blocking of the fish blocking mesh at the earlier fish fry period, on one hand, the phenomenon that the fish fry bites tender rice seedlings can be avoided, on the other hand, fish fry loss caused by irrigation and drainage can be avoided, the rotted fish blocking mesh can be adopted as fertilizer to allow fry growth, and no garbage is generated.