Improving service quality through investment and construction has become an important means for crowdsourcing logistics service platforms to enhance their competitive advantages. To maximize platform expected revenue, the condition that fierce competition existed in crowdsourcing logistics platforms and investment construction much-needed to improve the quality of service was considered. The consumer and distribution personnel's utility function was built. On this basis, a model was discussed based on the two competing crowdsourcing logistics platform through the construction investment to improve the offline service quality. The optimal profit and pricing strategy of the two platforms under different investment conditions was analyzed. The research shows that when the service quality of the two crowdsourcing logistics platforms is equal, the quantitative distribution, price and profit of consumers and delivery personnel of the two platforms are equal. When one party adopts the investment strategy, it will be better than the one who does not adopt the investment strategy in terms of profit. When both sides adopt investment strategies and level the competitive advantage, the profit will decrease due to the increase of cost.