In order to improve the accuracy and success rate of geographical guidance, according to the structural characteristics of the roll-pitch electro-optical pod, a mathematical model of geographical guidance was developed through three steps: first, establishing the coordinate system; second, solving the target coordinates; and third, calculating the frame angle. Speed forward feed and small domain search modes were introduced on this basis. The frame angle calculation error affected by inertial navigation measurement error and target distance was simulated, and the results show that the longitude, latitude, and heading angle errors had a greater influence on the pitch angle calculation error; nonetheless, the errors of elevation and horizontal attitude angle had a greater influence on the calculation error of the roll angle. Improving the positioning accuracy of inertial navigation can further reduce the frame angle calculation error and improve the geographical guidance accuracy. However, when the heading angle decreases below 0.1 degrees and the horizontal attitude angle decreases below 0.05 degrees, then the influence weight of the attitude angle error also decreases. The improvement in guidance accuracy is no longer evident when attitude angle errors are reduced. Increasing target distance sharply decreases the error of frame angle calculation. Finally, the guidance test with pitch and roll mean square errors of less than 0.12 degrees shows the algorithm's accuracy and the simulation analysis's effectiveness.