The invention discloses operation device and method for multiplying and adding a floating point vector. The device comprises a multiplier selecting unit, n multiplication units and n addition units, wherein the multiplier selecting unit is used for selecting the (m+1)th part of a second source operand floating point vector and outputting the (m+1)th part to the n multiplication units according toa value m of a fourth source operand, wherein m is less than or equal to n-1; the multiplication units are used for respectively multiplying the (m+1)th part of the selected second source operand floating point vector and n parts of a third source operand floating point vector and outputting an operation result from the multiplication operation to the corresponding n addition units; and the adding units are used for respectively adding the n parts of the operation result from the multiplication operation and n parts of a first source operand floating point vector to obtain a result of multiplication and addition. Therefore, a shuffle shift instruction in the operation of the floating point vector can be saved, the length of a program is reduced, and the operation efficiency and velocity of a microprocessor are improve when the multiplication and addition operations are carried out.