Abstract This study proposes a novel approach to obtain less conservative conditions for the robust stability analysis for time-varying delay systems with parameter uncertainties and nonlinear perturbations. Specifically, first, we divide the time-varying delay into non-uniformly subintervals and decompose the corresponding integral intervals to estimate the bounds of integral terms more exactly. Second, novel delay-derivation-dependent stability criteria are derived by introducing a parameter γ in the Lyapunov–Krasovskii functional. Third, we define some new variables to deal with uncertain parameters. Finally, two numerical examples are presented to demonstrate the effectiveness and advantages of the theoretical results.