This paper discusses the nonlinear errors for a novel gap variation-type thick film capacitive micro-displacement sensor. The micro-displacement sensor is developed for measuring the PZT displacement based on the pattern of PZT deformation-force sensing-displacement. In theory, The capacitor detects the micro-displacement driven by the PZT ceramic，and the variation of capacitance can be transformed into real-time output voltage signals. In this process, there would be some nonlinear errors. Based on the structure and operational principle of the sensor, possible nonlinear errors and their causes are analyzed. Then targeted measures are adopted to deal with them. Results show that the sensor’s linearity can be improved by effective compensating methods.