Provided are a fungus-sourced high-temperature neutral Family-45 cullulase as well as a coding gene and application thereof. The cullulase has optimal pH value of 5.5, and optimal temperature of 60° C., has certain enzyme activity in alkaline condition, and has good alkali resistance, maintains about 70% enzyme activity in optimal condition after being processed at 90° C. for 1 hour, maintains about 50% enzyme activity in optimal condition after being processed in boiling water for 1 hour, and can be well applied in c and other fields.