In order to know about the change of concrete stress and internal forces during the construction period of one highway tunnel, to evaluate the safety of lining structure, to take precautions against early diseases and to avoid loss in result of structural instability, linear arrays of fiber Bragg grating sensor in series were used for continuous monitoring typical lining cross section based on wavelength division multiplex. A mass of initial data was acquired. Furthermore, internal forces and early concrete stress of lining were analyzed according to time stress curve and internal force diagram. It has been found that fiber Bragg grating is highly adaptable to tunnel environment and the test method is of high accuracy. Therefore, the method discussed in this paper can be used for field test of tunnel structure extensively.