To monitor the structure deformation of an underground tunnel, a high-resolution wireless inclinometer was developed in this paper,and the algorithm of temperature compensation and digital filter applied to the wireless inclinometer were analyzed. First, based on complex conditions in the underground tunnel, the hardware structure of the wireless inclinometer was presented combined the Micro-electromechanic System( MEMS) with the Wireless Sensor Network(WSN) technology and the software processes of wireless communication and PC interface of the inclinometer were described. Then the effects of different environment parameters on the inclinometer were discussed according to the conditions of underground tunnel such as wide-range temperature changes and frequent vibration. Finally, the temperature compensation and resistance to vibration interference were achieved, and the accuracy of the inclinometer was improved. Experimental results indicate that the precision of the inclinometer is 0.05° in the range from -30°to 30°, which meets the design requirements of the underground tunnel for the monitoring deformation.