Barca made five changes from the side that beat Juventus, with goalkeeper Marc-Andre ter Stegen returning after a lengthy injury layoff and Gerard Pique returning from supension, while Sergio Busquets Sergino Dest and Pedri were handed starts.
The Catalan giants got off to a dream start Lionel Messi got the opener in the fifth minute with a smashing spot-kick into the bottom corner after he was tripped inside the box by Denys Popov.
Barcelona missed some good chances to get two-goal cushion in the game but Dynamo eventually grew in the game and Vitaliy Buyalskiy came close to levelling matters ten minutes before the break with a free header that was parried over the crossbar by Ter Stegen.
The hosts had another chance just before the break to make it 2-0 after Dest beat his marker on the byline and played a cut-back into the box but Pedri's shot produced a good save from shot-stopper Ruslan Neshcheret.
Ronald Koeman's charges were struggling to break down Dynamo in the early exchanges of the second stanza but Pique finally made it 2-0 in the 65th minute with a powerful header from a short corner floated inside the box by Anssumane Fati.
Viktor Tsygankov pulled a goal back for the Ukrainian side in the last quarter of an hour with a close range finish from a rebound after ter Stegen spilled Benjamin Verbic's initial shot.
Dynamo pressurised Barca in search of a consolation in the closing phase, with Blaugrana looking to punish them on counter-attack but neither scenario yielded the desired return as the Spanish giants held on to clinch their third win in as many matches to remain at the top of Group G.