In this research, wave propagation analysis in polymeric smart nanocomposite micro-tubes reinforced by single-walled carbon nanotubes (SWCNT) conveying fluid is studied. The surrounded elastic medium is simulated by visco-Pasternak model while the composite micro-tube undergoes electro-magneto-mechanical fields. By means of micromechanics method, the constitutive structural coefficients of nanocomposite are obtained. The fluid flow is assumed to be incompressible, viscous and irrotational and the dynamic modelling of fluid flow and fluid viscosity are calculated using Navier-Stokes equation. Micro-tube is simulated by Euler-Bernoulli and Timoshenko beam models. Based on energy method and the Hamilton’s principle, the equation of motion are derived and modified couple stress theory is utilized to consider the small scale effect. Results indicate the influences of various parameters such as the small scale, elastic medium, 2D magnetic field, velocity and viscosity of fluid and volume fraction of carbon nanotube (CNT). The result of this study can be useful in micro structure and construction industries.