Abstract: Objective The arching mechanism and evolution law of the surrounding rock pressure arch in deep-buried urban soft rock tunnels remain unclear, often resulting in overly conservative design of underground support structures and increased project costs. Therefore, it is necessary to further study the characteristics of pressure arches in urban deep-buried soft rock tunnels under support conditions. Method Taking the tunnel interval between Fuhua Road Station and Xietaizi Station of Chongqing Rail Transit Line 18 as the engineering background, a combined approach of numerical simulation and laboratory model testing is employed to analyze the evolution law of pressure arches under support conditions at burial depths ranging from 50 to 500 meters. The dynamic development trend of pressure arch with increasing burial depth under support conditions is investigated. The results of numerical calculation are compared with laboratory model test monitoring data to verify the reliability of the numerical model calculation results. Result ＆ Conclusion Under support conditions and burial depths of 50 to 500 meters, the stress state of the tunnel surrounding rock lies within the rock bearing zone and the original in-situ stress zone. The pressure arch overall shape remains largely unchanged with the increasing burial depth, and compared to the unexpanded inner boundary, the outer boundary expands outward by 6.7% to 21.6% before stabilizing. Under support conditions, the dynamic development of the pressure arch is only minimally affected by the burial depth. When the burial depth exceeds 300 meters, the extend of the pressure arch remains essentially unchanged.