Based on MATLAB/Simulink tool and the theory of measurement-based load modeling method, the influences of fuel cell(FC) generation system on the load modeling of distribution network are studied. Through the analysis of dynamic operation characteristics in the transient state processes of FC generation system, FC generation system is regarded equivalent to a generalized dynamic load which consumes negative power, and can be described by second-order differential equations. Then the synthesis load model of distribution network with FC generation system is proposed. Such model is represented by the generalized synthesis load model(GSLM) of induction motor in parallel with FC and static load. The validity, the ability of interpolation and extrapolation and the stability of parameters of the proposed GSLM are testified by the analysis of simulation modeling of three typical operation states with different interference intensities.