An existing Wireless Power Transmission (WPT) system based on electromagnetic inductive coupling for Video Capsule Endoscopes (VCE) was optimized, which focused on improving its energy transmission system. A portable WPT platform was presented with the detailed information about system optimization. The proper structure of transmitting coil was selected through comparing magnetic density and uniformity, then the transmission frequency of the system was chosen in terms of analyzing the resonance principle and testing the quality factors (Q-factor). The frequency stability was improved using an adjustable inductance in series with the transmission circuit, and the transmitting current fluctuation along with the frequency was measured. The experiments show that the optimized WPT system can transmit an output power of 78.4 mW for the VCE, in stable and reliable functions. During experiments, the VCE produces clear images with a resolution of 320 × 240 at a frame rate of 30 frames per second. The feasibility of VCE for the clinical applications has been improved as the portable energy transmission system has a higher transmission efficiency and stability and can support the VCE to work continuously in a higher resolution and frequency.