It has been experimentally proved that the intense laser-driven capacitor-coil target can generate a strong magnetic field of several hundred Tesla. The basic model of the magnetic field generated by this experimental method and its development process are introduced. Comparisons are made between three magnetic field diagnostic methods commonly used in laboratory, including: B-dot, Faraday rotation and proton backlight, it is found that the first two methods can only obtain a limited number of magnetic field values far away from the target in the experiment. The values of the magnetic field at the target obtained by the simulation tool and the value of the measurement point cover a span of several orders of magnitude, which is prone to errors; the proton backlight diagnosis can obtain the global magnetic field information in the experiment, which can better meet the needs of the magnetic field diagnosis of the coil target. Because the magnetic field of the coil target is strong and sustainable for a long time, and has a certain controllability in space-time distribution, we applied it to the study of magnetic reconnection, and have successfully obtained the reconnection characteristics, such as outflow. In addition, the coil target has also been applied in many aspects, such as the confinement of charged particles and the study of magnetohydrodynamics, which will provide new ideas for the research of related problems in laboratory.