Abstract: Due to poor working conditions and other reasons, diesel engine used in self-propelled intelligent flower leaf industrial hemp harvesting equipment（hereinafter referred to as hemp diesel engine）often experiences one type or another of malfunction, among which holding bush is one of the most common and serious faults in hemp diesel engines．Starting with analyzing stress on crankshaft bearing shells of diesel engines, a diagnostic approach for bearing shells was proposed based on working principle of diesel engine lubrication system and fault phenomenon of bearing shells．Specific reasons for bearing shells were analyzed in detail, and effective measures were provided to prevent and reduce bearing shells．And it creatively proposed adding a set of oil advance lubrication device to original lubrication system of hemp diesel engines, fundamentally avoiding occurrence of bearing failure．