Yellow leaf disease caused by areca palm yellow leaf phytoplasma(AYLP) and the yellow leaf virus disease caused by Areca palm velarivirus 1(APV1) are two of the most serious diseases affecting areca palm trees, causing huge economic losses to the areca palm industry in Hainan, and the establishment of rapid detection techniques is of great importance for the early warning and prevention and control of both diseases. In this study, multiplex PCR was used to detect areca AYLP and APV1 simultaneously, i.e. after the first round of nested PCR for AYLP, the multiplex PCR was used to amplify the two pathogens simultaneously, and the results were finally observed by electrophoresis. As results, by optimizing the multiplex PCR concentration system and annealing temperature, AYLP and APV1 were successfully amplified in one system, and two specific size bands of 525 bp and 311 bp were obtained. The results of multiplex PCR were in complete agreement with the results of single PCR, and compared with the single PCR assay, the multiplex PCR method streamlined the operation steps, improved the detection efficiency and significantly reduced the detection cost, providing a new method for the routine diagnosis of areca palm yellow leaf disease and yellow leaf virus diseases. Therefore, this technique has important applications in the routine detection of AYLP and APV1.