The invention discloses free-cutting steel containing relatively high content tin, and belongs to the technical field of metallurgy. The free-cutting steel is characterized in that the problem that at present, the tin content is too high, so that the hot shortness of free-cutting steel is too high is solved by conducting alloying of Mo, W and a rare earth element, that is, La on the free cutting steel. The free-cutting steel comprises the following basic chemical elements in percentage by mass: 0.02-0.77 percent of C, 0.01-0.10 percent of Si, 0.30-1.50 percent of Mn, 0-0.035 percent of S, 0-0.025 percent of P, and 0.05-0.35 percent of Sn, also comprises the main alloying elements in percentage by mass: 0.2-0.75 percent of Mo, 0.4-2.25 percent of W, and 0.002-0.020 percent of a rare earth element, that is, La, and further comprises the rest ingredients of Fe and inevitable impurities. The alloying process of Mo, W and the rare earth element La is mainly realized in the refining process. The free-cutting steel has relatively high hot rolling process performance and relatively high rolled metal surface quality when having high cutting performance, and is a low-sulfur and lead-free environmental-friendly material meeting the development tendency.