By adsorption,this paper systematically studies adsorption and adsorption mechanism of Pb2+ by celery residue.Experimental results showe that: with the smaller size of celery residue,Pb2+ adsorption rate is increased.Under the same Pb2+ initial concentration,with the addition of more celery residue,Pb2+ adsorption rate is increased.Under the same addition amount of celery residue,with the addition of Pb2+ initial concentration,adsorption rate is also increased.Orthogonal tests show that: the optimum adsorption conditions for the wastewater pH is 4,the temperature is 50 ℃ and soaking time is 5 hour.The influence order of 3 factors is pH,soaking time and temperature.Celery residue on Pb2+ adsorption with single molecule layer absorption dominant,and adsorption isotherm is fit to Freundlich adsorption isotherm.The adsorption rate for celery residue to Pb2+ is quick at the beginning,and then becomes slowly after 40min.Second kinetic model better describes the adsorption kinetics of celery residue.The best s/l radio of Pb2+(50 mg/L) adsorption by celery residue is 15 g/L.In the low concentration of Pb2+ solution(≤20 mg/L),the adsorption of celery residue is better than activated carbon.