The invention relates to a shear strengthening method of a concrete beam. The method comprises the following steps of: selecting a
fiber reinforcement with a
diameter of 8mm-25mm according to the shear span area length of the concrete beam and the strength of concrete; drilling corresponding holes in a shear span area of the beam, wherein the
diameter of the holes is 1.5 to 1.5 times larger than the
diameter of the
fiber reinforcement, the distance between adjacent holes is 1 to 2 times larger than the distance between hoop reinforcements in the shear span area, and the holes are positioned in the midpoints of the cross beam of the beam in the width direction; filling
epoxy resin glue in the holes; applying prestress on the selected
fiber reinforcement; and inserting the fiber reinforcements with prestress into the holes to form a shear
system formed by longitudinal reinforcements, the hoop reinforcements, the fiber reinforcements, and
epoxy resin glue and the concrete. The method has the beneficial effects that the damage to a concrete protecting layer limited to the concrete beam itself is avoided, the middle of the beam is provided with the holes, and the fiber reinforcements are fully wrapped by
epoxy resin and concrete, so that a greater anchoring force is generated, the material
utilization rate is improved, and the debonding failure of the fiber reinforcements and the concrete is also prevented, and thus the utilization value of the fiber reinforcements is increased.