An internal high-speed transmission connector of an SAS5.0 server comprises a PCB, a male joint connector and a female joint connector. The female joint connector is fixed on the PCB, the male joint connector is inserted into the female joint connector for fixed connection, the male joint connector is internally provided with two male joint matching groups, each male joint matching group comprises two adjacent male terminal accommodating layers, male terminals and a male joint iron sheet arranged between the male terminal accommodating layers, each male terminal accommodating layer is provided with male terminal accommodating grooves, the male terminals are placed in the male terminal accommodating grooves, orientations of the male terminal accommodating grooves in the two adjacent male terminal accommodating layers are opposite to each other, the female joint is internally provided with two terminal accommodating areas, the upper and lower sides of each terminal accommodating area are provided with female terminal accommodating grooves, female terminals are placed in the female terminal accommodating grooves, and during insertion, the four layers of male terminals are communicated with the four layers of female terminals. According to technical schemes of the invention, the terminal layers of a four layer laminated design satisfies the requirement of high density of a server mainboard, and a spring improves the mechanical maintenance force.