Zero crossing detection circuit and air conditioner

The invention discloses a zero crossing detection circuit and an air conditioner and relates to the technical field of the air conditioner. The zero crossing detection circuit is to solve unnecessary power consumption caused by power loss of the air conditioner in a standby status. The zero crossing detection circuit comprises a voltage dividing unit, a control unit, and a detecting unit; the voltage dividing unit is used for dividing voltage in a loop; the control unit is connected with a first level end, a second level end, a control signal input end, a first node and a second node, so that the first node and the second node are connected or disconnected under control of the control signal input end; the detecting unit is connected with the first node, the second end of a power grid power source, the first level end, the second level end and the detection signal output end, so that voltage on the first level end or the second level end is output from the detection signal output end under control of voltage