Wheatstone bridge is a bridge circuit composed of four resistors. It uses the change of resistors to measure the change of physical quantity. In this paper, the basic concept of the Wheatstone bridge is first introduced, then the theoretical analysis and practical experiment are carried out. Finally, how to build, test and characterize a Wheatstone bridge is understood. It is also pointed out that in application, a Wheatstone bridge circuit is typically used to measure small variations in resistance that the sensing element produces in response to stress, temperature and other phenomena.