The invention discloses a navigation satellite high-precision time service system with a constant temperature circuit and a method. The navigation satellite high-precision time service system includes a satellite signal receiving module, a work state judging module, a crystal oscillator control module, a constant temperature crystal oscillator, a sampling module, a reference signal output module, a constant temperature module and a constant temperature compensation module; and the crystal oscillator control module, the constant temperature crystal oscillator, the sampling module, the constant temperature module and the constant temperature compensation module are integrated in a sealed metal shell. The temperature of the system is monitored and adjusted through the constant temperature module and the constant temperature compensation module, and therefore, the accuracy of time service can be greatly improved, and the technical indexes of products and work efficiency can be improved.