The invention relates to the field of civil engineering construction, and provides a construction process of a mold-free concrete spraying beam. The construction process is used for reinforcing engineering of anchor rod lattice beams in slope protection engineering, foundation pit engineering and the like. The construction process of the mold-free concrete spraying beam comprises the following steps that A, slope treatment is carried out, specifically, a mountain body is excavated in a graded mode according to the designed slope rate, the height of each grade is 8-10m, and the slope surface isleveled or sprayed concrete is adopted for initial protection; B, anchor rod installation (including prestressed anchor rods and non-prestressed full-length bonding anchor rods) is carried out; C, full-length steel bars are arranged along the slope surface in a # shape, a square steel bar cage is formed through binding of stirrups, the sprayed concrete is sprayed back and forth for a plurality oftimes along the steel bar cage in a wet spraying mode to form the lattice beams, and the anchor rods are located at the cross joints of the lattice beams; and D, after the strength of the concrete meets the requirement, the prestressed anchor rods are tensioned and locked, the step A to the step C are repeated to enter the next grade of slope prestressed anchor rod lattice beam construction, andthe construction process is worthy of application and popularization.