Disclosed is an adjustable transmission device for measuring transverse parameters of beams, including: a CCD transmission support assembly, an external transmission rod, the CCD transmission support assembly is connected with a support block, and the support block is provided with the slotted set screw with flat point, and is connected with a limit block via a first fastener; a snap ring is arranged in the rear of the external transmission and is matched with a base; the base is connected with the CCD fixed plate via a second fastener. The external transmission rod is provided with a second groove for mounting the first retaining ring, and a side of the first retaining ring is sequentially provided with a vacuum observation window, a second retaining ring, a head assembly, a retaining sleeve and a screwing mechanism.