Cross-border e-commerce is a powerful embodiment of the digital development of foreign trade transactions, but the cross-border logistics model constrains the development of cross-border e-commerce. The article outlines the cross-border e-commerce business process and proposes a smart logistics system for cross-border e-commerce that combines blockchain technology. The transportation cost, cargo damage cost, penalty cost, distribution center cost and information technology cost of cross-border e-commerce logistics transportation are taken as the objective function to construct a logistics distribution path optimization model. Then a genetic algorithm is introduced to solve the model and obtain a cost-effective cross-border e-commerce logistics distribution path optimization scheme. The optimal transportation time obtained in the simulation of the GA algorithm-solving model is only 34.76h, and the total distribution cost of the optimal distribution scheme obtained by the model after 160 iterations is 1068.7 yuan. The cross-border e-commerce logistics path optimization model can obtain the optimal logistics and distribution scheme under the consideration of time window constraints, and combined with the verification of the intelligent logistics system, it can be seen that the total logistics and distribution cost of 10 customers in the distribution area is 10956.02 yuan. The optimization of the cross-border e-commerce logistics model can be realized based on big data technology and blockchain technology, which lay the foundation for high-quality cooperation and the development of international foreign trade transactions.