The invention belongs to the technical field of real-time monitoring of fracturing construction data of oil and gas wells, and particularly provides a high-frequency sampling device of a union type pressure sensor, which comprises the union type pressure sensor, a resistor, a selector, a gain amplifier, a filter circuit, an analog-to-digital converter, a processor, an Ethernet interface, a POE (Power over Ethernet) switch and an upper computer, wherein the union type pressure sensor, the resistor, a multiplexer, the gain amplifier, the filter circuit, the analog-to-digital converter, the processor, the Ethernet interface, the POE switch and the upper computer are sequentially and electrically connected, the POE switch is electrically connected with the multiplexer, the gain amplifier, thefilter circuit, the analog-to-digital converter and the processor. The high-frequency sampling device of the invention solves the problem that a conventional data acquisition system is difficult to directly read out an important pressure change point on a curve in the construction process and has a great influence on the effect evaluation after fracturing construction; the high-frequency samplingdevice can accurately record the important pressure change points, improve the accuracy of the effect evaluation after fracturing and improve the refinement level of fracturing construction.