A routing path calculation method, comprising: determining (S101, S802) the number n of passing constraint condition or conditions, and correspondingly copying (S101, S802) n network topology layer or layers, wherein n is a positive integer, wherein the passing constraint condition indicates that one or more links or nodes are required to be passed; configuring (S102, S803) different layer attribute information for an original network topology layer and the n copied network topology layer or layers; modifying (S103, S804) connection of at least one link of each network topology layer according to the n passing constraint condition or conditions, and establishing (S103, S804) connection of at least one one-way link between two network topology layers with adjacent layer attribute information; calculating (S104, S805) a k-optimal path from a starting point of a head network topology layer to an ending point of an end network topology layer by use of a k-optimal path algorithm; and performing (S105, S807) restoration processing on the layer attribute information of at least one node in the k-optimal path to convert the at least one node into a node in the original network topology layer to obtain a final path; wherein before determining (S101, S802) the number n of the passing constraint condition or conditions and correspondingly copying the n network topology layer or layers, further comprising: detecting (S801) whether the passing constraint condition or conditions are valid or not; and in a case where the passing constraint condition or conditions are valid, executing the operation of determining (S101, S802) the number n of the passing constraint condition or conditions. determining (S101, S802) the number n of passing constraint condition or conditions, and correspondingly copying (S101, S802) n network topology layer or layers, wherein n is a positive integer, wherein the passing constraint condition indicates that one or more links or nodes are required to be passed; configuring (S102, S803) different layer attribute information for an original network topology layer and the n copied network topology layer or layers; modifying (S103, S804) connection of at least one link of each network topology layer according to the n passing constraint condition or conditions, and establishing (S103, S804) connection of at least one one-way link between two network topology layers with adjacent layer attribute information; calculating (S104, S805) a k-optimal path from a starting point of a head network topology layer to an ending point of an end network topology layer by use of a k-optimal path algorithm; and performing (S105, S807) restoration processing on the layer attribute information of at least one node in the k-optimal path to convert the at least one node into a node in the original network topology layer to obtain a final path; wherein before determining (S101, S802) the number n of the passing constraint condition or conditions and correspondingly copying the n network topology layer or layers, further comprising: detecting (S801) whether the passing constraint condition or conditions are valid or not; and in a case where the passing constraint condition or conditions are valid, executing the operation of determining (S101, S802) the number n of the passing constraint condition or conditions. detecting (S801) whether the passing constraint condition or conditions are valid or not; and in a case where the passing constraint condition or conditions are valid, executing the operation of determining (S101, S802) the number n of the passing constraint condition or conditions. <EOS>