The invention discloses a normal temperature extra soft adhesive for externally repairing side edge scratches of a retreaded tire, comprising the following raw materials in parts by weight: 80 parts of natural standard rubber, 20 parts of butadiene rubber 9000, 100 parts of CaCO3, 10 parts of carbon black N754, 5 parts of 99.5-percent zinc oxide, 3 parts of stearic acid, 1 part of anti-aging agent 4010, 1 part of anti-aging agent RD, 1.5 parts of anti-aging agent DFC, 60 parts of engine oil, 3 parts of sulphur, 1.5 parts of accelerating agent M and 0.2 part of accelerating agent TMTD. The invention also discloses a repairing process of side edge scratches of a retreaded tire. The normal temperature extra soft adhesive improves the soft characteristics of adhesive under normal temperature, and the plasticity reaches 0.90-0.95 and is one time higher than that of the traditional bonding adhesive. In the process, the traditional ponderous heating and extruding tools are not used and simple repairing tools are used, thus a user can do as own wishes during operation. The repaired part of the tire has neat appearance, and the normal temperature extra soft adhesive has high production efficiency and saves energy.