Searches for the direct third generation squark production in proton-proton collisions at ${\sqrt{s}=\mathrm{13~TeV}}$ are presented using data recorded by the CMS experiment corresponding to integrated luminosity of $\mathrm{35.9~fb^{-1}}$. No significant deviation from the standard model has been observed in either of the searches. The exclusion limits have been set in terms of Simplified Model Spectra on pair production of third generation squarks. The combination of analyses with final states containing 0,1 or 2 leptons excludes a stop ($\mathrm{\tilde{t}}$) mass of 1050 GeV when the neutralino ($\mathrm{\tilde{\chi}_{1}^{0}}$) is massless and a neutralino mass of 500 GeV for a stop mass of 900 GeV. The exclusion limit on the sbottom ($\mathrm{\tilde{b}}$) goes up to a mass of 1225 GeV when the neutralino is massless and a neutralino mass of 600 GeV is excluded for a sbottom mass of 625 GeV.