Objective To investigate the effect of precision nutrition management on the weight gain and pregnancy outcome in the patients with rapid gestational weight gain (GWG).Methods A total of 121 pregnant women with regular antenatal check-up and rapid GWG in this hospital from July 2022 to May 2023 were selected as the study subjects and divided into the observation group (n=58) and control group (n=63) by the random number table method.The two groups all received the conventional antenatal check-up,health-care and health education.The observation group simultaneously received the precision nutrition intervention for 4 weeks,in which one extra meal was replaced with 30 g of low glycaemic index nutritional formula pow-der.The diet situation and physical activity levels in the observation group were investigated before interven-tion and during the intervention period.The baseline information,post-intervention body weight,delivery body weight and pregnant maternal and neonate outcomes were collected in the two groups.Results Compared with before intervention,whole grains and miscellaneous beans[0(0,30.0)g/d vs.0(0,2.5)g/d],fish and shrimp[65.0(0,130.0)g/d vs.0(0,100.0)g/d],vegetables[(310.5±98.9)g/d vs.(248.2±117.9)g/d],iron[20.30(18.70,23.90)mg/d vs.18.75(14.80,22.80)mg/d]intake and weekly activity time[350(280,420) min vs.210(150,280)min]during the intervention period in the observation group were increased,fruits[179.0(145.0,238.0)g/d vs.200.0(179.0,366.0)g/d],total energy[1702(1608,1837)kcal/d vs.2055 (1848,2327)kcal/d],saturated fatty acids[11.50(8.20,15.80)g/d vs.15.75(12.30,19.00)g/d]intake and proportion of fat calories[(31.71±5.22)％ vs.(35.12±6.17)％]were decreased,the differences were statis-tically significant (P<0.05).Compared with the control group,the intervention period[0.45(0.29,0.63)kg/week vs.0.63(0.50,0.88)kg/week]and the weekly weight gain in 4 weeks after the intervention[0.50 (0.34,0.64)kg/week vs.0.70(0.50,0.93)kg/week],GWG excess ratio (60.3％ vs.77.8％) in the observa-tion group were lower,and the differences were statistically significant (P<0.05).Compared with the control group,complicating anemia during pregnancy (15.5％ vs.31.7％),macrosomia (5.2％ vs.17.2％),incidence rate of adverse delivery outcomes (1.7％ vs.12.7％) and neonatal birth weight[(3292.2±420.9)g vs. (3497.6±454.7)g]in the observation group were lower,and the natural labor process was shorter[5.17 (3.33,9.15)h vs.10.00(6.37,18.00)h],the differences were statistically significant (P<0.05).Conclusion Preci-sion nutrition management could effectively control rapid GWG and the increasing velocity of gestational weight.