Method and plant to implement the continuous thermal hydrolysis of sludge to be treated containing organic matter, the method comprising at least: a. a step for de-structuring said sludge to be treated producing de-structured sludge; b. a step for the thermal hydrolysis of said de-structured sludge within a thermal hydrolysis reactor producing hydrolyzed sludge; c. a step for cooling said hydrolyzed sludge; said step for de-structuring consisting in: introducing said sludge to be treated into a dynamic mixer; heating said sludge coming from said dynamic mixer, this heating being obtained by the introduction, into a heat exchanger, on the one hand of said sludge coming from said dynamic mixer and, on the other hand, of said hydrolyzed sludge, this introduction inducing said cooling.