The invention discloses a package type reinforcing device and construction method. An isolating layer and a reinforcing layer arranged on the periphery of the isolating layer in a covering mode are included. The package type reinforcing construction method comprises the following steps that S1, the isolating layer is laid on the surface of a loose structure; S2, reinforcing steel bars are bound onthe surface of the isolating layer, a template is arranged in a supporting mode; S3, the reinforcing layer is poured; S4, the template is removed; S5, a translation underpinning structure is mounted;S6, whole translation construction is carried out, and translation is carried out to a designated position; S7, basic connection of the loose structure is completed; and S8, the reinforcing layer andthe isolating layer are disassembled. An outer contour of the loose structure can be well coincided when the reinforcing layer is poured, and it is ensured that no gap exists with the structural outer surface; the reinforcing layer has good strength and rigidity after reaching the strength, can provide stable and lateral restrain with full section for the loose structure; and the isolating layeris arranged between the reinforcing layer and the loose structure and can play the protection action on the loose structure, further cannot damage the outer surface, and the reinforcing layer is conveniently disassembled to recover the original appearance of the loose structure.