The hybrid multilevel inverter is widely used because it can output more levels and uses fewer switching devices. However,the traditional phase disposition pulse width modulation (PD-PWM) strategy is used for hybrid cascaded H-bridge 13-level inverters with a voltage ratio of 3:1:1,and the power of each unit is unbalanced. In order to achieve the goal of power equalization,an improved hybrid modulation method for the hybrid 13-level topology is proposed. Based on this method,it further reconstructs the triangular carrier under PD modulation and adjusts the output pulse of the high-voltage unit. Under laboratory conditions,taking the modulation degree of 0.9 as an example,the switching losses of the three low-voltage units L₁,L₂,and L₃ are 4.6 W,4.4 W,and 4.2 W respectively. The switching losses are basically equal. The output power of L₁,L₂,and L₃ is basically the same. The output power of high-voltage unit H₁ is 51.7 W, and the power of the three low-voltage units is 17.2 W. The output power ratio of high-voltage and low-voltage units is close to 3:1. The research shows that the switching losses of the three low-voltage H-bridge units are the same and the power of the four units is balanced. The power switches of the high-voltage and low-voltage parts work at the fundamental frequency and high frequency respectively,and the harmonic characteristics are good.