In this paper, we first achieve nanosecond-scale dissipative soliton resonance (DSR) generation in a thulium-doped double-clad fiber (TDF) laser with all-anomalous-dispersion regime, and also first scale the average power up to 100.4 W by employing only two stage TDF amplifiers, corresponding to gains of 19.3 and 14.4 dB, respectively. It is noted that both the fiber laser oscillator and the amplification system employ double-clad fiber as the gain medium for utilizing the advantages in high-gain-availability, high-power-handling and good-mode-quality-maintaining. DSR mode-locking of the TDF oscillator is realized by using a nonlinear optical loop mirror (NOLM), which exhibits all-fiber-format, high nonlinear and passive saturable absorption properties. The TDF oscillator can deliver rectangular-shape pulses with duration ranging from ~3.74 to ~72.19 ns while maintaining a nearly equal output peak power level of ~0.56 W, namely peak power clamping (PPC) effect. Comparatively, the two stage amplifiers can scale the seeding pulses to similar average power levels, but to dramatically different peak powers ranging from ~0.94 to ~18.1 kW depending on the durations. Our TDF master-oscillator-power-amplifier (MOPA) system can provide a high power 2-μm band all-fiber-format laser source both tunable in pulse duration and peak power.