Because of its simple structure, high precision ranging and good anti-interference ability, the laser fuze system with geometric intercepting ranging has a larger requirement in low-cost ammunition, as well as the ranging of the point of explosion and accuracy are all closely related to the system parameter design. In order to meet the requirements for the design of the parameters of the laser geometry intercepting ranging system, the geometric intercepting interval echo power model was established and the influence of the change of these parameters on the distance of work was analyzed, and the relation between work distance and system parameter was revealed. Then the value domain of parameter meeting these conditions was calculated. Through comparson and analysis, the optimal parameters of the system in theory obtained were d=63 mm, θr=35 mrad, θt=10 mrad, αr=0.5π rad, αt=0.45π rad. The experiment platform of the laser ranging simulation was designed to verify design results. Then the experimental results were consistent with theory. So it indicates that the design parameters can meet the system requirements. This research can provide reference to the laser geometry intercepting ranging system′s parameters.