In view of the safety of the tunnel lining formwork trolley, with a case study of bifurcated long highway tunnel, a secondary lining trolley formwork system of the tunnel has been designed according to the size of the lining trolley, with a calculation made of the internal force and deformation of the longitudinal and circumferential ribs, followed by a further calculation of the internal force and deformation of the trolley door structure based on ANSYS software. The results show that the strength and rigidity of the formwork system and the trolley structure meet the design requirements; according to the calculation results, it is recommended that the secondary lining concrete should be poured symmetrically to keep the trolley stress symmetrical, with a horizontal support of I20a I-steel be added at the longitudinal interval of 1 m at the bottom longitudinal beam of the portal frame, and the circumferential secondary rib angle steel should be added between the two main ribs as well.