Christophe Mandanne, Claudio Beauvue, Fatih Atik, Younousse Sankhare and Steeven Langil all got on the scoresheet for the hosts, while Cedric Bakambu had temporarily brought the visitors back into the match at 3-1.
The home side got off to a great start and were ahead inside 10 minutes, when Mandanne received a pass across the face of goal before tapping in at the far post.
Guingamp then doubled their lead in the 17th minute after Beauvue headed past Simon Pouplin at the far post.
The hosts thought they had added a third on the half-hour mark when Mandanne knocked the ball into the back of the net at the near post, but this was chalked off as the referee deemed Mustapha Yatabare to be guilty of pulling Cedric Kante's shirt.
However, they made it 3-0 just moments later when Atik curled a free kick in off the left post from the edge of the box to effectively put the game to bed before the break.
Sochaux got off to the perfect start after the break, when Bakambu struck a low effort from the edge of the box which Assembe spilled into his own net.
However, Guingamp crushed any brief hopes of a fightback from the away side when Pouplin spilled a catch leaving Yatabare to pass inside to Sankhare, who slammed home the fourth.
Guingamp completed the rout in stoppage time when Langil ran inside from the left and smashed a right-footed effort into the top corner from outside the box.
The victory moves Guingamp up to 12th, while winless Sochaux remain bottom of Ligue 1.