Abstract: Supposing that three or more failure modes arise synchronously to be very small probability event, the relationship between limit state functions was established for different failure modes by using linear regression method. A double integration model was built for reliability calculation of mechanical components at dependent failure modes. The model can be used after a linear transformation if a square, cube or exponential relationship appears between the limit state functions. Pin reliability was computed at dependent failure modes by the model and validated by the Monte Carlo method. The result confirms the validity of the double integration model.