In this paper, the complex multi-symplectic method and the implementation of the generalized sinhGordon equation are investigated in detail. The multi-symplectic formulations of the generalized sinh-Gordon equation in Hamiltonian space are presented firstly. The complex method is introduced and a complex semi-implicit scheme with several discrete conservation laws (including a multi-symplectic conservation law (CLS), a local energy conservation law (ECL) as well as a local momentum conservation law (MCL)) is constructed to solve the partial differential equations (PDEs) that are derived from the generalized sinh-Gordon equation numerically. The results of the numerical experiments show that the multi-symplectic scheme has excellent long-time numerical behavior and high accuracy. generalized sinh-Gordon equation, multi-symplectic, complex method, Runge-Kutta methodsThe multi-symplectic integrator, proven to be a very robust framework for the accurate, efficient and longtime integration of some nonlinear evolution equations, was widely investigated during the last decade [1][2][3][4][5][6][7][8][9][10][11][12] . Bridges, Reich and Moore presented the concept of the multi-symplectic integrator and applied it to solving nonlinear wave equation [1][2][3][4] and nonlinear Schrödinger equation [2] . Subsequently, the multi-symplectic schemes were constructed to obtain the solutions to several physically important nonlinear evolution equations, such as membrane free vibration equation [5] , Boussinesq equation [7] , KdV equation [8][9][10] , Schrödinger equation [11] , Ginzburg-Landau equation [12] and so on, numerically.The generalized sinh-Gordon equation, first appearing in the propagation of fluxons in Josephson junctions between two superconductors [13] , then in such fields as differential geometry, solid state physics, nonlinear optics, and dislocations in metals, has been theoretically studied to a great extent [14,15] . However, the numerical method for sinh-Gordon equation has not been reported formally. In this paper, the multi-symplectic formulations of the generalized sinh-Gordon equation are presented according to the multi-symplectic theory of Bridges. A semi-implicit complex scheme with several discrete conservation laws is constructed to solve the multi-symplectic partial differential equations (PDEs) that are numerically derived from the generalized sinhGordon equation. Finally, the numerical experiments are presented to illustrate the good numerical behavior of the multi-symplectic method.