Abstract: One-dimensional (1D) nuclear magnetic resonance (NMR) logging is a branch of NMR logging technology that evaluates reservoir properties by measuring and inverting transverse relaxation time (T₂). To meet the requirements of reservoir pore structure characterization and fluid identification, various multi-activation schemes with different waiting times (TW), echo spacings (TE), and echo numbers (NE) have been gradually developed, along with corresponding data processing and interpretation methods. Based on the activation schemes and measurement principles of 1D NMR logging, this paper systematically analyzes the NMR relaxation mechanisms, multi-echo-train inversion methods, and interpretation approaches for different activations. To address the challenges associated with low-resistivity oil and gas reservoirs, complex wettability, and tight oil and gas reservoirs, this study comprehensively reviews the innovations in processing and interpretation methods for multi-activation NMR logging data, establishes a technical framework for multi-activation data processing and interpretation, and summarizes the applicability of different activations and processing–interpretation methods based on practical applications. The results indicate that 1D NMR log processing and interpretation technology has evolved from single echo-train inversion to joint inversion of multiple echo trains, from linear inversion to nonlinear inversion, and from assuming water-wet conditions to considering diverse wettability conditions. However, existing activation designs and processing–interpretation frameworks still exhibit insufficient adaptability to different reservoir types, wettability conditions, and fluid viscosities, as well as low signal-to-noise ratios and limited inversion accuracy. To address these challenges, corresponding strategies and research directions are proposed to promote the development of 1D NMR logging technology toward high-capacity acquisition, intelligent processing, and refined interpretation.