A method for preserving and conditioning beef comprises: cleaning and chopping picked fresh beef, dipping in composite essential oil prepared from clove essential oil, cinnamon essential oil and illicium verum essential oil for 30 s and taking out and draining slightly; placing the beef dipped into a modified atmosphere packaging box and fast precooling; inflating gas of mixed proportion into the cooled modified atmosphere packaging box with beef for preservation packaging and then storing at the low temperature of 0-4° C. The shelf life of the beef packaged by the method is up to 24 d. The aerobic bacterial count is not over 6.0 lgcfu/g. A total volatile basic nitrogen TVB-N value is not over 20 mg/100 g and belongs to the range of second freshness. The beef is stable in color, is cherry-red, has the advantage of good preservation effect and is used for cooking preserved cooked beef.