The present application provides an optical module and parameter transmission method, detection method, control method thereof, and a fronthaul system. The parameter transmission method includes: generating, in response to at least one of a plurality of registers of a far-end optical module becoming a first source register, an uplink optical signal according to ID information and a register value of the first source register, where the first source register is a register having a changed register value of the plurality of registers, and register values of the registers have a mapping relationship with performance parameters of the far-end optical module; and transmitting the uplink optical signal to a near-end optical module of a near-end node.