The former England captain signed a five-month contract with the Ligue 1 leaders on transfer deadline day in January.
The 37-year-old was put through his paces in training with club director Leonardo watching from the sidelines.
Beckham travelled to Spain with Carlo Ancelotti's men for their 2-1 first-leg win over Valencia in the UEFA Champions League on Tuesday.
He could make his PSG debut against Sochaux on Sunday, but the midfielder's lack of match fitness may mean he comes off the bench.
Beckham has not played a competitive match since helping former side the Los Angeles Galaxy to the MLS Cup in December.
PSG sit six points clear at the top as they search for their first top-flight title since 1993/94.