The invention provides endogenous gene screening and application suitable for identifying a copy number of exogenous genes of sugarcanes. Nucleotide sequences of a primer and a probe are SEQ ID NO.1, SEQ ID NO.2 and SEQ ID NO.3; and the PCR (Polymerase Chain Reaction) amplification length of the endogenous genes is 95bp. In view of the problems that an existing method for identifying the copy number of exogenous genes of sugarcanes is complicated, the working amount is great, the efficiency is low, the accuracy is low and the like, the invention provides the endogenous gene screening and application suitable for identifying the copy number of the exogenous genes of the sugarcanes; an established construction method of an endogenous gene and exogenous gene standard curve is simple to operate, high in sensitivity, high in specificity, high in accuracy and high in repeatability; and a scientific, accurate and practical detection method is provided for identifying the copy number of the exogenous genes of transgenic sugarcanes.