The invention discloses a linear assembly instruction diversity conversion based DSP soft error detection method which can solve the problem that the conventional DSP soft error detection methods are large in performance cost. The DSP soft error detection method includes: dividing a program into storeless basic blocks, establishing a program control flow diagram, recognizing circulations, screening out circulations capable of arranging a software pipeline; reinforcing the program, adding error detection instructions to the program, performing equivalent conversion on a part of instructions through an instruction diversity conversion method, and performing double calculation on the rest instructions, inserting the detection instructions before instruction storage and instruction jumping, optimizing the detection instructions through DSP instruction condition execution characters and the equivalent conversion method, and reducing the performance cost due to reinforcement through the delay error processing method for the circulations capable of arranging the software pipeline; and executing the reinforcement program, and detecting soft errors during operation. The DSP soft error detection method is a DSP reinforcement method of pure software, is high in detection rate of date errors, and is low in performance cost of reinforcement.