The invention provides a high-efficiency composite guanidine-based paper-making fungicide, which belongs to the technical field of paper-making fungicide production. In parts by weight, the fungicide comprises the following components: 10-30 parts of guanidine-based polymer, N-octyl 5-15 parts of isothiazolinone, 150-450 parts of diethylene glycol, 0.5-1.5 parts of dodecyl dimethyl benzyl ammonium chloride, 0.3-1.8 parts of hydroxymethyl cellulose, o-phenyl Potassium hydrogen diformate 0‑100 parts. The guanidine-based polymer is polyhexamethylene biguanide hydrochloride. Polyhexamethylene biguanide hydrochloride is broad-spectrum antibacterial, has killing ability to Gram-positive bacteria, Gram-negative bacteria, fungi and yeast, and can be used to produce antibacterial paper for health and hygiene products to replace silver-containing libraries At the same time, the polyhexamethylene biguanide hydrochloride solution also improves the physical properties of the paper, water absorption, strength after being wetted with water, and air permeability, so it is a papermaking fungicide with excellent performance. The synergistic effect is a compound TS-302 papermaking fungicide with high efficiency and broad spectrum.