The invention proposes a C-frequency band directional diagram forming coupling heat antenna. With the structural design of multi-layer coupling parasitic radiation units, equivalent radiation aperture of the antenna is improved, and the directional diagram coverage performance of the antenna is effectively improved on the premise that the requirement of heat environment is met; by a feed network design combined with a design of a multi-layer radiation structure, the directional diagram forming of the antenna is fulfilled, and the coverage characteristics of a low-elevation angle and high-gain directional diagram conformity to the demand of a measurement and control link are achieved; no direct metal connection is arranged among multi-layer coupling parasitic radiation patches, multiplex of a patch substrate and an thermal insulation material of the antenna is realized, and thus, a thermoelectric integrated design is achieved; the antenna radiation requirement is met, and meanwhile, an effect of preventing an external heat environment is achieved. The antenna design can be promoted to the designs of forming heat antennas for measurement and control frequency bands such as L, S, C, X, Ku, Ka and the like, a favorable reference basis is provided for the deigns of the forming heat antennas, and the antenna has strong applicability.