The invention discloses a Ca-S composite free-cutting non-quenched and tempered steel for cutting which has high cutting property and the manufacturing method thereof. The steel is composed of 0.44% to 0.49% of C, 0.30% to 0.60% of Si, 1.20% to 1.50% of Mn, 0.08% to 0.12% of V, no more than 0.30% of Cr, Ni and Cu, 0.040% to 0.065% of S, no more than 0.035% of P, 0.001% to 0.010% of Ca, 0.01% to 0.03% of Al, and the balance Fe and unavoidable impurity. According to the method, the compositions of inclusion in steel are controlled by ladle argon blowing and Ca-S composite processing, casting blank is poured by continuous casting, the average temperature for heating billet in a heating furnace is 1180 DEG C to 1220 DEG C, the heating time is 2 to 3 hours, the rolling starting temperature is 1100 DEG C to 1150 DEG C, the rolling finishing temperature is 850 DEG C to 1000 DEG C, the cooling speed of the rolled steel is 1.5 DEG C per second to 2.5 DEG C per second, the cooling bed cooing in pile temperature is 600 DEG C to 700 DEG C. The steel has superior mechanical property and free-cutting property.