Experiments on control effects of pre-emergence herbicides on maize of conservation tillage were carried out in field.The results showed that the quantity control effects of weeds of 38% atrazine 150 ml/667m²,90% acetochlor 140 ml/667m²,72% propisochlor 150ml/667m²,2,4-D-butyl 70 ml/667m² 45 days after spraying were 81.40%,80.69%,79.23% and 50.47% respectively;But 50% 2,4-D-butyl+acetochlor,40% acetochlor+atrazine,50%2,4-D-butyl+atrazine and 42%2,4-D-butyl+propisochlor+atrazine have improved the control effects and the quantity control effects of weed 45 days after spraying were 84.94%,86.33%,89.53% and 85.47% respectively.It could improve the control effect if soil of 2-3cm was mixed up.The quantity control effects of weeds of 38% atrazine 150 ml/667m²,90% acetochlor 140 ml/667m²,72% propisochlor 150 ml/667m²,72% 2,4-D-butyl 70 ml/667m²,50% 2,4-D-butyl+acetochlor,40% acetochlor+atrazine,50% 2,4-D-butyl+atrazine and 42%2,4-D-butyl+propisochlor+atrazine were 87.42%,85.61%,84.02%,52.41%,92.74%,91.30%,91.92% and 89.42%.