Flexible and rigid materials, such as stainless steel cable (SSC), stainless steel cable with blades (SSCB), stainless steel cable mesh (SSCM), and carbon fibre reinforced polymer grid (CFG), were used to reinforce printed concrete. Based on the directed double-sided shear test, the shear responses of printed concrete, such as the failure mode, shear strength, and shear load–displacement curve, were obtained, and the enhancement efficiencies of different reinforcing methods were discussed by considering the variation in the ratio of reinforcement. Furthermore, the mechanical mechanism was proposed, and prediction models were established based on the different contributions of the flexible and rigid reinforcing materials to the shear behaviour of printed concrete. The results indicated that the stiffness of the reinforcing materials evidently affects the shear performance of printed concrete, and lateral reinforcement is beneficial for improving the shear strength and toughness of printed concrete.