In an electro-optical countermeasure system， an infrared warning device is generally used to implement target guidance for the acquisition and tracking device. To scientifically evaluate the guidance capability of the equipment， this study initially establishes the transformation models of the target’s azimuth and elevation in the infrared warning coordinate system and the acquisition and tracking coordinate system. The calculation model of guidance error is determined by utilizing the law of error propagation. The calculation methods for the coordinate transformation parameters necessary for guidance error calculation are provided. Secondly， warning， guiding， and tracking information at multiple positions are set and generated. Subsequently， this information is utilized to solve the calculation parameters of guidance error， and the guidance errors at different airspace positions are calculated. Finally， the accuracy of the calculation results is analyzed， and the guidance capability is evaluated. The simulation results indicate that this method can analyze the guidance error of the target airspace through information from multiple positions， and the difference between the simulated error and the original error is less than 0.1°. This approach offers a feasible means for comprehensively evaluating the guidance capability of the equipment in different airspace ranges.