We present the design of a compact channel drop filter based on 2D photonic crystals on silicon-on-insulator platform. The proposed device consists of three channel sections with line defect waveguides as the bus and drop waveguides and L3 cavity as the resonator. The input and output ends of the bus waveguide are connected to silicon strip waveguides through tapered waveguide regions for efficient mode transmission. Each L3 cavity filters one resonant wavelength, which will be coupled to the drop waveguide. The effect of the size and position of the structural parameters on the proper selection of resonant wavelengths and drop efficiencies is studied. The device performance has been numerically analyzed, and thermal stability is studied using the 3D finite-difference time-domain method. The proposed device can filter three wavelengths in the C-band with minimum channel spacing of 3.03 nm. With the tapered-coupled bus waveguide, drop efficiency has been improved from 77% to 91%, and the quality factor and linewidth are found as 5042 and 0.31 nm, respectively. The footprint of the filter is 116 μm² per channel section. The proposed device is suitable for practical wavelength division multiplexing applications in optical communication systems.