The invention discloses a divide-by-three circuit without a divider. An Esum adder in the circuit is used for adding all binary numbers located at even bits in binary data so as to obtain an addend Esum. An Osum adder is used for adding all binary numbers located at odd bits in the binary data to obtain an addend Osum. A first multiplexer is used for comparing the addend Esum with the addend Osum;if the addend Esum is greater than or equal to the addend Osum, the difference between the addend Esum and the addend Osum is calculated and output, if the addend Esum is smaller than the addend Osum, the difference between the addend Osum and the addend Esum is calculated, the difference value is shifted leftwards by one bit, and therefore two times of the difference between the addend Osum andthe addend Esum is obtained and output. According to the divide-by-three circuit without a divider, hardware resources can be saved, and power consumption and cost are reduced.