The invention discloses a perforation parameter optimization method for maintaining balanced expansion of staged fracturing cracks of a horizontal well. The perforation parameter optimization method comprises the following steps: S1, estimating an inlet net pressure value of the fracturing cracks of the horizontal well; s2, calculating a perforation hole friction coefficient required for maintaining balanced expansion of the horizontal well fracturing cracks; s3, calculating perforation characteristic parameters; s4, determining optimal perforation parameters; s5, establishing a complete fluid-solid coupling hydraulic fracture expansion calculation model; and S6, predicting and evaluating the fracturing effect of the target block after the optimized perforation parameters are adopted. According to the method, the stress field heterogeneity, fluid-solid coupling in the dynamic hydraulic fracture expansion process and the multi-fracture stress shadow effect are considered, the influencecaused by the perforation hole abrasion phenomenon is also considered, the method can be effectively used for maintaining fracture balance expansion of horizontal well staged fracturing, operation iseasy, and practicability is achieved.