Based on the need to improve the detection accuracy, efficiency and traceability of low temperature co-fired ceramics (LTCC), a set of LTCC laser thickness measuring system was designed. For the problem of measuring accuracy was difficult to meet, the existing error was analyzed, the use of adjusting fixture for thickness measurement eliminated coaxial error and linearity error, optimized the design structure to reduce inclination error, eliminated repeatability errors through cyclic sensor calibration, reduced mechanical vibration error through data optimization and filtering processing, improved the system measurement accuracy. Compared with the actual product thickness data, the final accuracy error ≤ 5 μm, which meets the application requirements of the product and has a broad application market.