Abstract: With the feature of a short development cycle, and the use of commercial shelf devices, picosatellites cannot follow the traditional reliability assessment for larger satellites which builds the system reliability model with components. The reliability assessment system of picosatellites based on experimental data is proposed. The reliability assessment of ZDPS-2 satellites is realized by building different hardware and software failure models respectively. The model of hardware failures is based on the ordering constraint model and the Bayesian parameter estimation method, and the equivalent factor of the different experimental environment to the satellite working environment is considered. ZDPS-2 satellite hardware reliability level is estimated as 0.85 at the end of 3 months. The model of software failures is fitted with the nonhomogeneous poisson process (NHPP) model with the change point. The logistic model is chosen as the test coverage model. According to ZDPS-2 satellite software failure results, the average time between failures is 217 h. The ZDPS-2 satellite test results confirm that the reliability meets the requirements for the growth test design and mission requirements.