The utility model provides a bidirectional equal-length prefabricated lattice beam. The prefabricated lattice beam is formed by a plurality of prefabricated cross-shaped beam body units in a matrix arrangement, tiling and lap joint mode. Each prefabricated cross-shaped beam body unit is formed by intersecting a cross beam and a longitudinal beam; anchor head parts are arranged at the intersectionsof the cross beams and the longitudinal beams; the corner of the cross interface at the joint of the cross beam and the longitudinal beam is arc-shaped; the anchor head part comprises a groove and abase plate placed at the groove; anchor holes for anchor rods or anchor cables to penetrate through are formed in the groove and the base plate. The utility model has the characteristics of simplifying the construction steps, shortening the construction period, reducing the construction risk, realizing standardized management production, ensuring the product quality, and being economical, practical and environment-friendly. According to the technical scheme, an existing cast-in-place anchor rod (cable) lattice beam can be replaced to reinforce the side slope, the side slope reinforcing structure has outstanding advantages in emergency rescue and reinforcement of the side slope, and the side slope reinforcing structure is also suitable for rapid reinforcement construction of the side slopein highway reconstruction and expansion.