To provide a power transmission mechanism for a multicompressor allowing easy belt stretching work and capable of prolonging service life of a belt.

A V-shaped groove is formed on a front side of a pulley 41, and a V belt 47 is stretched. On the other hand, teeth are peripherally formed on a rear side of the pulley 41. Teeth are peripherally formed on a pulley 43 in the same way. A gear 45 is nipped and mounted between the pulleys 41 and 43. Power from an engine is transmitted by the V belt 47 to rotate and drive the pulley 41. The rotation of the pulley 41 is also transmitted to the pulley 43 through the gear 45. Consequently, the V belt 47 is merely stretched on one pulley, thereby facilitating belt stretching work.