the 808 nm high-efficiency laser diodes have many advantages, such as high output power, high reliabilities, compact sizes, which are widely used in many areas, such as industry, communication, science, medicine and biology. in order to improve the power conversion efficiencies of 808 nm laser diodes, the following requirements must be considered, such as loss of joule heating, loss by the carrier leakage, spontaneous radiation loss below the threshold current, loss by interface voltage defect, internal losses including free-carrier absorption loss and scattering loss. these losses above are closely related to the operating temperature of laser diode. in this paper, power conversion efficiency analysis is demonstrated from the aspects of the output power, threshold current, slope efficiency, voltage, and series resistance at different temperatures.. this is the first time that the detailed study has been carried out under various temperatures (up to the lowest temperature of -40 degrees c). and the detailed study above can be of benefit to designing the wafer epitaxial structure.