Polypyrrole (PPy)/graphene nainocomposite was prepared by methyl orange (MO) reactive template. By changing the amount of MO, the morphology of PPy can be controlled to range from nanoparticle to nanowire. Transmission electron microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and X-ray diffraction results demonstrated that the composites were successfully synthesized. The different morphologies of PPy/graphene nanocomposites had certain effects on the supercapacitor performance. The experimental results showed that the capacitance of PPy (nanoparticle)/graphene was higher than that of PPy (nanowire)/graphene. As a model, PPy (nanoparticle)/graphene was used to construct a supercapacitor. By changing the amount of pyrrole monomer, the performance of the supercapacitor prepared from different PPy content was studied in detail.