Provided in embodiments of the present invention are a method and device for implementing high-definition image capturing, comprising: collecting and acquiring image data of a first set format by using an image sensor, image processing the image data then encoding into modulated data of a second set format, converting the modulated data into an analog electric signal of a third set format by using a synchronous clock, and filtering the analog electric signal by using a filter circuit then transmitting via a coaxial cable. The above series of operations is capable of implementing the collection and processing of a high-resolution video, and solves the problem that existing high-definition camera are incapable of ensuring timeliness during a video transmission process and provides poor stability and reliability, while at the same time, employment of the present invention also allows an existing analog camera to use a cable device for video transmission, thus implementing full utilization of existing resources.