A calibration method for a driving current of a light source adapted to sequentially calibrate at least an optical navigation device, each including a light sensing device, a memory unit and a driving unit. The driving unit is electrically connected to the memory unit and a light source configured to receive a reflection light. The calibration method includes steps of: driving the light source to provide a beam through configuring the driving unit to supply a first driving current to the light source; configuring the light sensing device to generate a sensed light value; obtaining a second driving current through modulating the value of the first driving current according to the sensed light value; and recording the value of the second driving current in the memory unit and driving the light source to provide the beam according to the second driving current. A light sensing module is also provided.