A method for adjusting relative position of a lens module by using a
uniform light source is provided. The lens module includes a bottom
board, an image sensor, an adjusting module and a lens apparatus. The
image sensor is disposed on the bottom board and perpendicular to the
optical axis of the uniform light source. The lens apparatus is moveably
disposed in front of the image sensor. The adjusting module connects the
lens apparatus to the bottom board. The image sensor electrically
connects to a testing module, and the testing module electrically
connects to the adjusting module. The method includes: (a) receiving
specific signals from the corresponding specific areas respectively; (b)
processing the specific signals to determine an adjustment quantity; (c)
selectively adjusting the relative position between the image sensor and
the lens apparatus by adjusting the module according to the adjustment
quantity.