Considering the application requirement of compact and miniaturized pulse source, the design technique of the quasi-square wave pulse forming network with adjacent mutual coupling inductors is studied. Firstly, the network optimization technique based on the univariate search method is introduced, and the values of the inductance and capacitance and the analytical expressions of quasi-square wave are obtained. Then the equivalent decoupling circuit of the network with adjacent mutual coupling inductors is deduced. Based on the backtracking algorithm, the method for calculating the values of each element in the network is given. Finally, in cases of equal capacitance and constrained capacitance, the parameters of each element in the network are given. The numerical results show that the ideal quasi-square-wave pulse with a certain width flat-top can be produced by using the designed PFN with adjacent mutual coupling inductors. The ingenious design based on mutual coupling inductance is beneficial to the design of compact quasi-square wave pulse forming network.