A non-invasive fast blood sugar tester able to monitor multiple patient at same time is composed of a casing, a panel with at least one horn opening from which a central axle of a heating head is projected, a display screen, a power supply port, a computer communication port, a power switch and several indicating lamps, a central control chip, a microwave generator connected to said heating head, a DC power supply, a microwave power regulator, temp detecting and controlling unit, temp regulator, time regulator, and temp sensor on the top of said central axle of heating head. Its test method is also disclosed.