Objective This study aimed to develop ready-to-use standard strains of Salmonella typhimurium （S. typhimurium） TA97， TA98， TA100， and TA102 for mutagenicity testing.Methods Freeze-dried strains of S. typhimurium TA97， TA98， TA100， and TA102 at both high and low concentrations were quantified. The spontaneous reversion rate of the freeze-dried strains after 3， 5， 7， and 18 h was measured. Homogeneity， storage and transportation stability， spontaneous revertant frequency， and mutagenic agent mutation rate of the ready-to-use standard strains were evaluated following the CNAS-GL003 2018 “Guidelines for the Evaluation of Homogeneity and Stability of Proficiency Testing Samples” and GB 15193.4—2014 “National Food Safety Standard - Bacterial Reverse Mutation Test.” Standard deviations of spontaneous revertant frequency and mutagenic agent mutation rate test results between 20 ready-to-use standard strains and fresh strains were compared.Results High-concentration lyophilized samples had concentrations ranging from 10⁷-10⁸ CFU/sample， while low-concentration samples had concentrations ranging from 10⁵-10⁶ CFU/sample. The spontaneous reversion rate results after 18 h of incubation met the requirements of GB 15193.4—2014. Homogeneity results for the four ready-to-use standard strains showed F-values of 1.12， 1.05， 1.68， and 1.38， with F < F_0.05 （19，20）， meeting CNAS-GL003 requirements. The detection results for the four freeze-dried strains stored at 25 ℃ for 5 d， 4 ℃ for 14 d， and -20 ℃ for 6 months met storage and transportation stability requirements. The standard deviation of spontaneous revertant frequency in the 20 ready-to-use freeze-dried standard strains was smaller than that of fresh strains.Conclusion The ready-to-use standard strains developed in this study exhibit excellent homogeneity， storage， and transportation stability. Moreover， the stability of spontaneous revertant frequency in the ready-to-use freeze-dried standard strains surpasses that of fresh strains.