This study aims to investigate the soil stability at the end of working well during rectangular pipe jacking construction and its impacts on engineering safety, as well as the ground settlement issues induced by insufficient soil reinforcement at the end. Based on the Longgang Road utility tunnel project in Hefei, a scaled model of rectangular pipe jacking with a geometric similarity ratio of 1∶20 was fabricated, and model tests together with simulation verification were carried out to explore the influence of different reinforcement lengths on soil stability. The test results indicate that the soil reinforcement at the end can effectively reduce the ground settlement. The ground settlement at the front of the working well presents a V-shaped distribution during pipe jacking. When the reinforcement length increases from 0.30 m to 0.34 m, the maximum ground settlement is only reduced by 7.14%, and the improvement effect tends to be insignificant with further increase of the reinforcement length. The lateral earth pressure of the working well is concentrated in the upper area of the tunnel opening and increases with the increase of the jacking distance, reaching a maximum value of 647.435 kPa at the jacking distance of 400 mm. This study reveals the nonlinear relationship between reinforcement length and settlement control, and proposes 6 m as the economical reinforcement length for practical engineering applications.