For the decisionmaking problems with vague information, this paper presents a multiple attribute group decision making approach based on Pythagorean hesitant fuzzy entropy.Firstly, the axiomatic definition and calculation formula of Pythagorean hesitant fuzzy entropy are proposed. Classical normalization method may cause the loss of original information, in order to overcome the shortcoming, a least common multiple extended method is completed to normalize the Pythagorean hesitant fuzzy sets. This expansion method can effectively keep the original information. Then, taking Pythagorean hesitant fuzzy entropy as the difference degree of decision information, a multiattribute group decision making method is given to determine the weight when the attribute weight is completely unknown or partially known. Meanwhile, the distance and entropy measures of Pythagorean hesitant fuzzy numbers are put forward. Finally, an approach of TOPSIS based on Pythagorean hesitant fuzzy entropy is developed. At the same time, a numerical example of precision poverty alleviation project is provided to illustrate the feasibility and effectiveness of the proposed method.