With the development of distributed environments such as WSN and IoT, the evaluation of security state of them has become a key issue. As a visualized method of network penetration test, the attack tree has played an important role in network security evaluation. In an attack tree, nodes represent security states of nodes in the network, while edges represent conditions or tools that cause state transfers. However, traditional attack tree-based penetration test has several disadvantages, such as inefficient tool management. This paper proposes FATPET, a novel penetration test framework which is based on attack trees in distributed environment. In FATPET, we first improve traditional attack tree language, then describe the design rationale of FATPET, and finally we propose the improvement to attack tool management. The case-study indicates that distributed attack trees are helpful and effective in penetration tests in distributed environment.