The invention discloses a digital tilt sensor and a temperature nonlinear compensation method thereof. The digital tilt sensor comprises an MEMS (Micro-electromechanical Systems) sensor, a filter module, a microprocessor, a reference power supply module, a communication module and a voltage-stabilized power supply module, wherein the microprocessor contains an A/D conversion module, a temperature compensation module and a nonlinear compensation module. The MEMS sensor outputs an analog voltage signal containing tilt angle information, the analog voltage signal is output to the A/D conversion module by the filter module, and meanwhile, the MEMS sensor also outputs a temperature digital signal to the temperature compensation module. In the microprocessor, the outputs of the A/D conversion module and the temperature compensation module are integrated by the nonlinear compensation module, and then a tilt angle measured value digital signal is output. The temperature nonlinear compensation technology adopted by the temperature compensation module and the nonlinear compensation module makes up the defects that in the existing similar technologies, the temperature compensation error is large and the nonlinear error is obvious. The digital tilt sensor disclosed by the invention has the advantages of low cost, high measurement accuracy, vibration shock resistance, and applicability to wide-temperature harsh environments.