The invention discloses a reference gene for detecting gene transcriptional expression of Sitodiplosis mosellana under stress of different temperatures; the reference gene is RPL13 gene, having a nucleotide sequence show as SEQ ID NO. 1. The RPL13 reference gene selected herein can be expressed stably under the stress of each of the temperatures, 0 DEG C, 10 DEG C, 20 DEG C, 30 DEG C and 40 DEG C; therefore, the RPL13 gene may act as a reference gene in the study and analysis on the expression of functional genes of Sitodiplosis mosellana under the stress of different temperatures, and accuracy of the fluorescent quantitative PCR (polymerase chain reaction) method to detect gene transcriptional expression level of Sitodiplosis mosellana is improved; the problem of low accuracy of gene mRNA expression quantitative detection for Sitodiplosis mosellana due to mRNA expression stability differences of the reference gene is avoided, and references are also provided for subsequent quantification of Sitodiplosis mosellana genes at different temperatures.