A route determining method, comprising: • obtaining startpoint information and endpoint information of a required path, wherein the startpoint information comprises a sequence number of a startpoint performance optimization datacenter, POD, and a sequence number of a startpoint edge switch, and the endpoint information comprises a sequence number of an endpoint, POD, and a sequence number of an endpoint edge switch (step 101); • determining, from an n-dimensional Latin square, an element whose row number is the sequence number of the startpoint edge switch and column is the sequence number of the endpoint edge switch, wherein n is a quantity of edge switches in each POD, an element in the n-dimensional Latin square is corresponding to an aggregation switch in each POD, and n is an integer greater than 2 (step 102); • if the sequence number of the startpoint POD is the same as the sequence number of the endpoint POD, determining that the required path is the startpoint edge switch, an aggregation switch corresponding to the element in the POD, and the endpoint edge switch (step 106), characterized in that • if a data flow is from the startpoint edge switch to the endpoint edge switch, the method further comprises: ∘ determining, from a 2n-dimensional Latin square whose diagonal elements are the same, a wavelength element whose row is the sequence number of the startpoint POD and column is the sequence number of the endpoint POD, wherein elements in the 2n-dimensional Latin square whose diagonal elements are the same are corresponding to 2n optical carriers with different optical wavelengths; and ∘ determining that an optical carrier corresponding to the wavelength element is an optical carrier used for the required path. • obtaining startpoint information and endpoint information of a required path, wherein the startpoint information comprises a sequence number of a startpoint performance optimization datacenter, POD, and a sequence number of a startpoint edge switch, and the endpoint information comprises a sequence number of an endpoint, POD, and a sequence number of an endpoint edge switch (step 101); • determining, from an n-dimensional Latin square, an element whose row number is the sequence number of the startpoint edge switch and column is the sequence number of the endpoint edge switch, wherein n is a quantity of edge switches in each POD, an element in the n-dimensional Latin square is corresponding to an aggregation switch in each POD, and n is an integer greater than 2 (step 102); • if the sequence number of the startpoint POD is the same as the sequence number of the endpoint POD, determining that the required path is the startpoint edge switch, an aggregation switch corresponding to the element in the POD, and the endpoint edge switch (step 106), • if a data flow is from the startpoint edge switch to the endpoint edge switch, the method further comprises: ∘ determining, from a 2n-dimensional Latin square whose diagonal elements are the same, a wavelength element whose row is the sequence number of the startpoint POD and column is the sequence number of the endpoint POD, wherein elements in the 2n-dimensional Latin square whose diagonal elements are the same are corresponding to 2n optical carriers with different optical wavelengths; and ∘ determining that an optical carrier corresponding to the wavelength element is an optical carrier used for the required path. ∘ determining, from a 2n-dimensional Latin square whose diagonal elements are the same, a wavelength element whose row is the sequence number of the startpoint POD and column is the sequence number of the endpoint POD, wherein elements in the 2n-dimensional Latin square whose diagonal elements are the same are corresponding to 2n optical carriers with different optical wavelengths; and ∘ determining that an optical carrier corresponding to the wavelength element is an optical carrier used for the required path. <EOS>