The invention relates to a cultivation and management method of packhams through plain net rack top grafting and variety changing. The method is characterized by comprising the following steps of S1, selection of stocks; S2, selection of scions; S3, treatment of the scions; S4, treatment of the stocks; S5, grafting; S6, racking and corner opening; S7, cultivation of bearing branches in the current year; S8, pruning management; S9, bearing management; S10, management in the third year. Compared with a traditional mode of not building a net rack, the cultivation and management method of the packhams through plain net rack top grafting and variety changing has the advantages that flower buds are easier to form, a large number of secondary branches are formed by adopting new shoots after corner opening, and the building mode is more conductive to management and picking, so that the management and picking process is safer and more efficient compared with a traditional mode; a net rack built for top grafting trees is more conductive to ventilation and light transmitting, so that the fruit quality is significantly improved; branches on the back of the packhams cultivated on a flat shed rack are few, shaping and pruning mainly comprise bud picking and branch thinning, the pruning workload is greatly reduced, the packhams bears fruits early, the yield is high, and the quality is good.