The measure of fragment's speed is a difficult problem in missile damaging-flight tests, and exact measure results are very important for the evaluation of weapon's damage effect and other technical parameters. Based on domestic actuality, the basic principles of the measure and evaluation methods of missile fragment's speed are summarized. The error sources of measure and evaluation of fragment's speed are discussed in each method discussed in the research. In view of the characteristics of the missile damaging-flight tests and the actual instance of the range, the error and error sources of single fragment's speed under the method of Reticulate Targets Method are analyzed. The corrected error model and the technique of improving speed measure's precision are put forward. The flaw and improving direction of the scheme normally used are pointed out. The results of the research have partially applied to the missile damaging-flight tests.