Allergic inflammation is closely related to the activation of mast cells (MCs), which is regulated by its intracellular Ca²⁺ level, but the intake and effects of the intracellular Ca²⁺ remain unclear. The Ca²⁺ influx is controlled by members of Ca²⁺ channels, among which calcium voltage-gated channel subunit alpha1 C (Ca_V1.2) is the most robust. This study aimed to reveal the role and underlying mechanism of MC Ca_V1.2 in allergic inflammation. We found that Ca_V1.2 participated in MC activation and allergic inflammation. Nimodipine (Nim), as a strong Ca_V1.2-specific antagonist, ameliorated allergic inflammation in mice. Further, Ca_V1.2 activation in MC was triggered by phosphatizing at its Ser1928 through protein kinase C (PKC), which calcium/calmodulin-dependent protein kinase II (CaMKII) catalyzed. Overexpression or knockdown of MC Ca_V1.2 influenced MC activation. Importantly, Ca_V1.2 expression in MC had detrimental effects, while its deficiency ameliorated allergic pulmonary inflammation. Results provide novel insights into Ca_V1.2 function and a potential drug target for controlling allergic inflammation.