There are problems with high peak power and low energy conversion efficiency in electric quay cranes at ports. This paper proposes a method for trajectory planning and power optimization control of electric quay cranes. The energy coupling conversion relationship and operation characteristics of electric quay cranes are analyzed, and a dynamic equation of electric quay cranes is derived. Considering the environmental constraints of the working process of electric quay cranes, a B-spline curve for the trajectory of electric quay cranes is designed. Analyzing the relationship between power transmission and conversion of electric quay cranes, combining with dynamic characteristics, determining a quantitative description relationship between operating trajectory and path power, and establishing an electric quay crane trajectory-power model. With the goal of minimizing total electricity consumption, the trajectory of electric quay cranes is optimized to reduce power loss. Simulation examples are established in matlab, and the proposed method significantly improves the power optimization control of electric quay cranes under different working conditions, verifying the effectiveness and reliability of the method.