The invention discloses a multiplication and division device which is used for achieving division operation of any number of digits of unsigned or signed numbers and multiplication of any number of digits of unsigned numbers. The multiplication and division device comprises a data preprocessing device, an iterative operation unit, a division operation unit, a multiplication operation unit, an operation control counter and a result register, wherein the data preprocessing device is connected with a first operand, a second operand, a multiplication and division operation selecting signal and a division mode selecting signal and processes the first operand and the second operand according to the multiplication and division operation selecting signal and the division mode selecting signal, the iteration unit is used for conducting remainder zero fill and divisor shifting or multiplier shifting and multiplicand expanding according to the multiplication and division operation selecting signal, the division operation unit is used for generating a two-digit quotient and a remainder, the multiplication operation unit is used for generating a product result, the operation control counter is used for controlling the number of the operation digits of the iterative operation unit, and the result register is used for storing the quotient, the remainder and/or the product result.