A micro core-drilling testing system for high-pressure environment, including: a pressure chamber, a micro core-drilling testing platform and a control device. The micro core-drilling testing platform includes a lower tray, a middle tray, a hydraulic system, a stroke cylinder, a rock sample plate, a rock sample block, a pressure compensation device and a drilling rig. The drilling rig is configured to carry out core-drilling operation. The hydraulic system is configured to provide power for the drilling rig. The pressure compensation device is configured to balance the pressure inside the pressure chamber and the hydraulic system.