Abstract: The objective of this experiment was to evaluate the effects of crushing peanut straws on physical characteristics of total mixed ration（TMR） and production performance of Hu Sheep. Forty-eight healthy weaned male Hu sheep lambs with the body weight of（15.77±1.27） kg were randomly divided into control group（fed uncrushing peanut straws） and experiment group（fed with crushing peanut straws sieve diameter 8 mm）. Each group had six replicates and each replicate included 4 lambs. The pre-test period was ten days, and the test period was 30 days. Peanut seedling（crushing, uncrushing）, concentrate supplement and TMR for experiment group and control group were sampled by geometric method, once every 10 days. After mixing, quartering method was used for sampling. The average particle size, physical effective coefficient（pef）_＞8.00, pef_＞4.00, and physical effective neutral detergent fiber（peNDF） of the feed were determined by Pennsylvania sieve（PSPS）. The feed samples of each layer were weighed and used to measure the bulk density of the samples. Before and after the test, all sheep were weighed on an empty stomach, the initial and final weights were recorded. The average daily gain, average daily feed intake and feed to weight ratio were calculated. The economic benefits such as feed cost and profit were calculated. The results showed that the mean particle size, pef_＞8.00 and peNDF_＞8.00 of TMR decreased significantly after the crushing of peanut seedlings（P＜0.05）, and the bulk density of TMR increased significantly（P＜0.05）. The crushed peanut seedlings changed the distribution ratio of TMR material between layers of Pennsylvania sieve. Compared with the control group, the total weight gain, average daily weight gain and average food intake in the test group were increased by 12.20%, 12.14% and 3.77%, respectively, and the feed to weight ratio was decreased by 7.20%, but there was no significant difference（P＞0.05）. Compared with the control group, the cost of diet in the test group decreased by 0.69 yuan/kg, and the profit increased by 19.34 yuan/piece. The results indicated that after grinding peanut seedlings（sieve diameter 8 mm）, the particle size of TMR decreased, the bulk weight increased, and the peNDF_＞8.00 decreased, which improved the weight and feed utilization rate of male Hu sheep lambs, and could effectively save feed costs.