Durable flame retardant DM-3070 for Cotton fabric is non-formaldehyde phosphate ester flame retardant. DM-3070 could effectively crosslink cotton fiber with 2D resin as cross-linking agent.The fabric after flame retardant finishing has good flame retardant effect, washing fastness, and cloth formaldehyde content can be controlled within 75 mg/kg. Compared with the traditional cotton fabric flame retardant DM-3070 can effectively improve the production environment and performance, and laid certain foundation for completely formaldehyde-free durable flame retardant finishing.