Conventional reliability models for parallel systems are not applicable for the analysis of parallel systems with load transfer and sharing. In this short communication, firstly, the direct reliability model of load-sharing parallel systems is presented based on the Miner cumulative damage theory, the total probability formula and addition principle. Secondly, the parallel system reliability is calculated using Monte Carlo simulation when the component life follows the Weibull distribution. The research results show that the proposed reliability mathematical model and Monte Carlo calculation method can analyze and evaluate the reliability of parallel systems in the presence of load transfer well.