Abstract: In order to effectively damage an armored target with explosive reactive armor(ERA)，it is necessary to study how to avoid the explosive field of ERA.A calculation model for the operating range of proximity fuze based on the low trajectory of tank gun is established on account of the structure and action principle of ERA and high explosive antitank (HEAT) projectile. According to the geometrical relationship of the proposed calculation model，the limiting intersection position of HEAT projectile and ERA as well as the proper operating range of the first-stage proximity fuze can be worked out. The theoretically calculated value of limiting position and the relationship between the operating range of the first-stage proximity fuze and the velocity of HEAT projectile were derived by taking a HEAT projectile as an example.Experimental results show that the critical value of limiting intersection position of HEAT projectile and ERA is approximately equal to its theoretically calculated value，and the theoretical value of this calculation model has higher accuracy and has guiding significance for the actual project design.

Key words: proximityfuze, explosivereactivearmor, operatingrange, fuze-warheadcoordination