The present invention relates to a digital portable pulse oximeter and battery-powered control method thereof. The automatic switching of the power supply is achieved by adding a Hall circuit, and the data displayed is allowed to always face the users by adding an acceleration sensor to the circuit. The advantageous effects of the present invention compared with the prior art are: Users can always read the data from the front side no matter which way they move. The digital portable pulse oximeter of the present invention can be automatically turned on just by inserting a finger, without having to press the switch button, and cut off the power supply by pulling out the finger, as well as judge intelligently whether to continue the measurement after the finger has been pulled out. If yes, the power supply will stay on, which reduces the energy waste and low efficiency caused by the restarting program initialization, improves the use efficiency of the battery and prolongs the battery life.
