Abstract: Water leakage of construction joints of secondary lining of the mountain tunnels is closely related to the construction technology and quality of tunnels. In light of the construction defects of end formwork of traditional lining jumbo and improving the quality of construction joint of secondary lining as well as speeding up installation of water stop, improvement was conducted to end wood formwork, and a steel-wood combined end formwork was developed based on a tunnel on the second ring road of Jinan city. With this type of formwork, it offers a space for bending of exposed half-range water stop, eliminates the fixing and positioning bars to avoid damaging of water stop, saves installation cost during construction of secondary lining, improves water resistance of construction joints of secondary lining; its segmental design option facilitates processing, installation and demoulding of the end formwork, and significantly improves the construction speed and quality.