In this study, the combine impacts of nonlinear thermal radiation and chemical reaction on bioconvection flow of magneto-Sisko fluid along a stretching cylinder with motile microorganism are investigated. The effects of variable thermal conductivity and non-uniform heat source/sink are also taken into consideration in this mathematical modelling. The analysis is total theoretically and the current model depicts the influence of thermophoresis diffusion and Brownian motion using Buongiorno model. The proper scaling transformation are used to convert partial differential equations into ordinary differential equations and then numerically solved by Runge Kutta Fehlberg algorithm with the shooting technique. The salient physical aspects of flow parameters such as magnetic parameter, Sisko fluid parameter, heat source/sink parameter, buoyancy parameter, bioconvection parameter, and chemical reaction parameter on dimensionless velocity, temperature, concentration, and microbe concentration distributions are examined and illustrated graphically. The behaviour of various physical factors such as surface drag coefficient, heat transfer rate and density of the motile gyrotactic microorganisms are discussed in detail. It is found that higher values of curvature parameter reduce the velocity profile of the Sisko fluid. The study reveals that the thermophoresis diffusion parameter diminishes the temperature field as well as thermal boundary layer thickness. Additionally, the sketch indicates that the expanding the Peclet number augmenting the density of the motile microorganism.