As the tunnel is dug deeply, the composite stratum is tunneled through which is formed by the combination of two or more rock and soil layers with significant difference in mechanical response. It is found from the engineering practice that the scientific design and construction methods of tunnels in composite stratum are lacking. Therefore, it is necessary to carry out systematic research on composite stratum tunnel and put forward scientific design method to ensure the safety of construction and operation of this kind of tunnel. Thus, relevant aspects such as the composite formation tunnel progressive failure mechanism research, compound formation tunnel surrounding rock classification study, compound formation tunnel stability evaluation and composite formation parameters of spatial variability study present situation, problems and development tendency were summarized and generalized. And it stated that the design method of compound formation tunnel research was based on the progressive failure mechanism of the tunnel.