This paper is conducted on the adaptive fuzzy predefined time tracking control problem for a class of non-strict feedback stochastic nonlinear systems with input delay and error boundary constraints. Based on the fixed-time stability criterion for stochastic nonlinear systems, the stability criteria for the practically predefined time of the stochastic nonlinear system is developed. Additionally, an auxiliary system is constructed to address the computational complexity caused by the input delay, and an adaptive fuzzy controller is designed using backstepping technique via self-triggering mechanism. Under the proposed control scheme, it can be proven that the tracking error converges within a dynamically defined boundary within a predefined time, independent of the initial state and system parameters. Following the developed the stability criteria for the practically predefined time, the closed-loop system stability analysis is completed. Simulation results demonstrate the feasibility and superiority of the main findings.