An interface circuit and a communication device are provided. The interface circuit includes a transformer unit, a protection unit, and an interface unit. A secondary side of the transformer unit is connected with a chip. A first terminal of the protection unit is electrically connected with a center tap of a primary side of the transformer unit, and a second terminal of the protection unit is grounded. A first access terminal of the interface unit is connected with a first port of the primary side of the transformer unit, a second access terminal of the interface unit is connected with a second port of the primary side of the transformer unit, and a third access terminal and a fourth access terminal of the interface unit are electrically connected with the first terminal of the protection unit respectively.