Fracturing fluid filtration loss is a significant research topic related to fracture propagation, formation damage and the cost of hydraulic fracturing. To reduce the loss, nanoparticles have been used to enhance the fracturing fluid properties such as viscosity and well-building ability. In this work, silica nanoparticles (NPs) with different concentrations (0, 0.01, 0.03 wt%) were added into the viscoelastic surfactant (VES) fluid composed of cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal). A micro pore-throat structure was applied to investigate the flow characteristics of those three fracturing fluids with Deborah numbers (De) spanning from 1.52 to 73.2, and a Newtonian fluid was set as the control group. It was found that the flow patterns of VES solutions performed as the convergent flow similar to those of the Newtonian fluid at upstream, and turned into divergent flow with the gathering of streamlines at downstream. Surprisingly, the flow characteristics between VES solution with no nanoparticles and nanoparticle-enhanced the VES solution showed an insignificant difference with high flow rates (5 and 20 ml/h). The nanoparticle was unable to enhance or influence the properties of VES fluid when flowing through convergence divergence and divergence convergence structure. Neither the breakage nor the recombination of wormlike micellar were barely affected by the nanoparticle. (C) 2020 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers.