We report on a Q-switched Er-doped all-fiber laser based on a solution-processed Ti3C2Tx saturable absorber (SA). Ti3C2Tx is transferred to the fiber core region by optical deposition process through thermal effect. The Ti3C2Tx SA is clamped between two optical fiber connectors, which is flexible to integrate into the laser oscillator. The modulation depth and saturation incident fluence are measured to be similar to 3% and similar to 53.31 mu J/cm(2) at 1550 nm wavelength region, respectively. At a threshold pump power of 190mW, we get self-started stable Q-switched operation with single-pulse energy of 22.17 nJ and pulse duration of similar to 7.07 mu s. With the pump power varing from 190 to 280 mW, the repetition frequency (RF) changes from 52.8 kHz to 62.79 kHz. The maximum average output power is 2.14 mW, which corresponds to the single-pulse energy of 34.03 nJ. The short-term stability is obtained by measuring the RF and temporal sequences of output pulse for 12 hours. Moreover, the long-term stability is demonstrated by measuring the output power and repetition rate for one week, showing the highly stable operation of the Ti3C2Tx fiber laser, for the first time as far as we know.