The invention discloses a method for breeding meloidogynes by utilizing a single allosome of a separated root system of a non-exogenous cultured water spinach, and the method comprises the following steps: (1) preparing the separated root system of the water spinach: seeding the seeds of the water spinach onto a flat plate of a 1% water agar medium, cutting root tips when the seeds grow into rootsystem with the length of about 3-4cm, inoculating the root tips onto the flat plate of a non-exogenous separated root system culturing medium, and growing a large number of separated roots after 15-20 days; and (2) inoculating and breeding the meloidogynes: preparing oocysts of the meloidogynes into an egg grain suspension solution, inoculating the egg grain suspension solution onto the separated roots, obtained in the steps (1), of the water spinach, and culturing for 50-90 days, thereby obtaining a large number of signal meloidogynes. The method provided by the invention is high in breeding rate, simple in operation, difficult in pollution, wide in application scope and strong in practicability; the problem of difficulty in obtaining a large number of purified meloidogynes is solved; and the defects of the method for breeding the meloidogynes by utilizing potting seedling that time is wasted, a large space is occupied, the method is limited by natural and environmental conditions of seasons, the meloidogynes are easily polluted by other organisms, and the like, are avoided.