The invention discloses a detailed model of a static self-shunt excitation system. The model comprises an organic terminal voltage measurement and comparison link for Vref and Vt, an excitation controller consisting of lead-lag correction units TC1/TB1 and TC2/TB2 and a gain amplification link KR, an excitation power unit simulated by a first-order inertia link, amplitude limiting links VRMAX and VRMIN, a terminal voltage Vt feedback link, a rectifier phase change voltage loss link KCIFD and excitation voltage output EFD, wherein a voltage difference DeltaV formed by terminal voltage Vt and reference voltage Vref is output to a rectifier for power amplification (KA and TA) through the lead-lag correction units TC1/TB1 and TC2/TB2 and the gain amplification link KR, the influence of upper and lower limit amplitude of the voltage is neglected, direct current no-load voltage Ud0 is obtained after the feedback effect of the terminal voltage Vt on voltage VR output by the rectifier, then the influence of the rectifier phase change voltage loss link KCIFD is subtracted, and the excitation voltage EFD is output. The model can be applied to a static self-shunt excitation system of which a thyristor adopts an incompletely cosine phase change triggering mode, and the accuracy of the conventional model can be improved.