Abstract: With the expending scale and the increasing operation complexity of power grid, reliability evaluation of transmission grid based on operation statistics can truly reflect the level of facility, structure and operation management of power network, which gradually gains the attention in many countries. After deep research on various countries' reliability evaluation indexes of transmission grid, a series of indexes for evaluating transfer capacity are proposed by considering circuit scheduling capacity. And the evaluation indexes of substation capacity is built, which include such two indexes as whole health degree and the substation capacity loss by considering in-substation network features. In the end, the accuracy of the existing indexes in evaluating the actual transfer capacity is further enhanced. The analysis of a case on the local power grid shows that these indexes are effective.