Situation display plays an important role in the combating simulation system based on HLA, especially in reflecting the status of combating entities and assisting decision-makers to modify the combating plan. The situation display systems used in combating simulation systems have betrayed the deficiencies of low adaptability and limited scope application field. These deficiencies restrict the widespread of situation display. Military symbols mapping and the pretreatment of simulation situation data are presented to improve situation display. Then a situation display system using the key techniques is realized. Finally, the advantages and disadvantages of the key techniques in situation display are summarized and the future is expected.