The invention discloses a fully degradable polyglycolic acid composite packaging material, which is prepared from the following components in parts by weight: polyglycolic acid, polycaprolactone, poly(L-lactide-Epsilon-caprolactone), anti-block agent, slippery agent, toughening agent, water barrier, chitosan, reinforcing fiber and the like. The invention also provides a preparation method of the fully degradable polyglycolic acid composite packaging material. The invention has the following advantages: microbial degradability and hydrolysis are good, the final form of the completely biodegradable material after decomposition is water and carbon dioxide, and there is no pollution to the environment; the material is safe and non-toxic, there is no potential health threat to animals and humans; the material has good mechanical properties, fully meets the needs of various applications of packaging materials; in the case of no influence on the chemical properties, the low-cost and no environmental pollution fillers are added, and the cost is effectively reduced; the preparation process is simple.