Abstract: Aiming at the problem of high respiratory temperature in the existing products of chemical oxygen self rescue respirator, a new type of chemical oxygen self rescue respirator is designed. The overall composition and gas circuit structure of the respirator are introduced. The comprehensive optimal determination of the key technical parameters and structure of the respirator, such as the formula of oxygen generator, the structure of respiratory gas circuit and gas circulation path, are discussed in detail. The comprehensive performance test results of the prototype show that the respirator not only ensures that the volume fraction of oxygen and carbon dioxide meets the requirements, but also realizes a lower respiratory temperature, and improves the safety and comfort of chemical oxygen self rescue respirator.