Abstract: This article proposes a balloon constant pressure-loaded positive pressure oxygen respirator and comparatively tests the breathing resistance value of balloon constant pressure-loaded respirators and spring-loaded respirators. The test results show that the breathing resistance value of balloon constant pressure-loaded respirators is lower and the amplitude of breathing resistance is smaller compared with spring-loaded respirators. When the load or the breathing capacity increased, the breathing resistance increased. When the load or the respiratory intensity reduced, the breathing resistance reduced.