The design of wireless sensor node in cold chain logistics was introduced, which solved the problem as high power consumption, channel collision and network complexity in cold chain logistics monitoring applications. Choosing MSP430F149 as the core processor and SHT11, PT1000 as temperature and humidity sensors, it can precisely collect data of temperature and humidity in different accuracy requirement. The wireless transmission was realized by SX1212. A kind of self-organized wireless protocol of star-shape was designed，in which physical layer was designed to fit the characteristics of cold chain logistics and the fusion of synergetic integration of binary tree and dynamic framed slotted ALOHA algorithm was used to avoid collision. Tests showed that the node had the advantage on ultra low power consumption and the rapid organizing of networks and it works well in cold chain logistic. The wireless sensor node can meet the requirement of cold chain logistics.