A remote monitoring system for farmland based on wireless image sensor network was put forward in order to obtain the farmland image and video information in real time. Aiming at the shortcomings of the current image sensor nodes, a low-cost high-resolution wireless image sensor node was designed based on CMOS image sensor chip and S3C6410 embedded processor. To ensure the stability and reliability of the node, the powerful embedded Linux operating system was employed as the software development platform. And based on this platform, a modular designing method was adopted to program the software system of the node in C/C++ language. Especially, a resolution adjustment algorithm based on driver and application layer cooperation was studied, which made the node had 10 different resolutions and the highest resolution was up to 5 mega pixels. More importantly, the resolution can be adjusted in real time according to the requirements of users when it was working, which made the node can meet the needs of users for different image accuracies. A wireless image sensor network was constructed by utilizing WiFi technology as well as the images and videos captured by the nodes were remotely transmitted to the server through the 4G network. In order to prolong the life cycle of the node, a solar power supply system was designed. A visual farmland information management software Webbased was developed in order to effectively store, manage and use the data captured by the nodes, and a convenient method was provided for a user to remotely access the acquisition networks and the data stored in the server. The system was deployed and tested for a long time. The test results showed that the system could work stably, as well as capture and transmit images with different resolutions according to the remote instruction. Moreover, the average time to capture and transmit one image with size of about 126KB was about 5.36s, and the average packet loss ratio of the network was about 1.67%. In the tests, the average delay for the client to open video monitoring was about 3.48s, and the video playing was smooth. Finally, the power supply system based on the solar energy could provide a stable power supply for the nodes in the long work. The tests validated that the remote monitoring system designed in this work can automatically capture images and videos of farmland in real time, transmit them to the server remotely, and satisfy the requirement of users for remote monitoring farmland.