A novel plasmonic sensor based on a photonic crystal fiber has been fabricated. Experimental results show that 2 cm is an optimal fiber length of the sensor for refractive index monitoring. It is found that the average wavelength sensitivity and the resolution of the proposed sensor are 4000 nm/RIU and 2.5 x 10(-5) RIU in the wind range of 1.3333-1.4035, respectively. In addition, this paper presents a set of operation flat roofs that is used in the side-polished fiber technique. Moreover, two effective methods of coating silver film are discussed in detail. The research in this paper has enlightening significance for exploring new optical fiber sensing technology and will open a new design methodology for optical fiber sensors. (C) 2020 Optical Society of America