A carry-skip one-bit full adder and a field programmable gate array device, the full adder includes: a first multiplexer, a second multiplexer, and an adder, the first multiplexer includes a first addend input end and a first constant input end configured to input a first constant to the first multiplexer; the second multiplexer includes a second addend input end and a second constant input end configured to input a second constant to the second multiplexer; when the first addend input end is not used for input of a first addend, and/or when the second addend input end is not used for input of a second addend, the first multiplexer selects to output the first constant input, and the second multiplexer selects to output the second constant input.