In this work, we study the X-ray bow-shock nebula powered by the mature pulsar PSR B1929+10 using data from XMM-Newton, with an effective exposure of ∼300 ks, offering the deepest investigation of this system thus far. We found the X-ray axial outflow extends as long as ∼8 arc minute behind the proper motion direction, which is a factor of two longer than the result reported in the previous study. Furthermore, we found evidence of two faint lateral outflows extending laterally with respect to the proper motion. We also found indications of spectral hardening along the axial outflow, suggesting that certain acceleration processes might occur along this feature.