The utility model relates to a public seat and particularly relates to a four-linkage turning and setting seat. The four-linkage turning and setting seat provided by the utility model comprises a chair back mechanism, a seat mechanism, a support mechanism and a handrail linkage mechanism, wherein the seat mechanism is mounted in the middle of the support mechanism and is in rotary match with the support mechanism; the handrail linkage mechanism is mounted at the upper end of the support mechanism and is in the rotary match with the support mechanism; the chair back mechanism is in connection and rotary match with the seat mechanism and the handrail linkage mechanism respectively; a connection rotary match point of the handrail linkage mechanism and the support mechanism is A; the connection rotary match point of the handrail linkage mechanism and the chair back mechanism is D; the connection rotary match point of the seat mechanism and the support mechanism is B; the connection rotary match point of the seat mechanism and the chair back mechanism is C; a linkable quadrilateral structure is formed by the connection rotary match points A, B, C and D to realize the four-linkage aim. The four-linkage turning and setting seat provided by the utility model is simple in structure; the quadrilateral linkage property is adopted to realize turning and setting utilization of the seat; the four-linkage turning and setting seat is flexible in structure, very comfortable in utilization and low in production cost.