A micro water pump capable of controlling flow precisely includes an upper cover, a valve seat, a water capsule seat, a base casing, a water capsule, a crank lever, a drive shaft, an eccentric wheel, a motor, a photoelectric switch, and an output circuit board. The output circuit board is electrically connected with an external motor controller. Through the photoelectric switch to detect the revolution of the motor and to cooperate with the external motor controller, the revolution of the motor control can be controlled precisely so as to get a stable water flow under different volumes and back pressures.