The invention discloses an MOCVD reaction room used for growing grapheme. The MOCVD reaction room mainly solves the problems that according to an existing epitaxy technique, the preparing efficiency is low, the crystalline quality is poor and the effective area is small. The MOCVD reaction room comprises source inlets (1), a top plate (2), purging air flow (3), an inverted tower-shaped spray head (4), quartz tubes (5), a groove graphite base (7), a resistance heating device (8), an air exhaust opening (9), a rotary support (10) and a supporting plate (11). The quartz tubes (5) are fixed to the upper portion of the supporting plate (11), the top plate (2) is located on the upper portions of the quartz tubes (5), the rotary support (10) is located between the quartz tubes (5) and is fixed to the supporting plate (11), the spray head (4) is fixed to the lower portion of the top plate (2), the purging air flow (3) is evenly distributed in a whole circular cavity between the quartz tubes (5) and the spray head (4), the heating device (8) is fixed to the upper portion of the support (10), and the groove graphite base (7) is located on the upper portion of the heating device (8) and right faces the lower surface of the spray head (4). The MOCVD reaction room is simple in structure, improves evenness of the air flow and the temperature in the reaction cavity and can be used for growing of high-quality and large-size grapheme.