The hydrothermal modified pyrolysis biochar(HMPC) has been obtained,by using the mixtures of chicken manure and corn cobs as raw materials,preparing pyrolysis biochar precursor(BPC),and modifying its hydrothermal reaction with urea. The adsorption capabilities of this HMPC for Cr(Ⅵ) and methyl orange(MO) in wastewater are evaluated. The results show that when the temperature is 25 ℃,initial pH value of Cr(Ⅵ) and MO are 2.0 and 6.5,stirring speed is 150 r/min,and dosage of HMPC is 1 g/L,the adsorption capaci...