A refrigeration system , comprising: a compressor , a condenser , an evaporator , and a lubrication circuit , the lubrication circuit comprising a post-lubrication flow path connected from the compressor into the condenser and the evaporator respectively; and a pre-lubrication flow path connected from the condenser and the evaporator into the compressor respectively; wherein the pre-lubrication flow path comprises a first branch connected to the condenser and a second branch connected to the evaporator respectively; and the post-lubrication flow path comprises a third branch connected to the condenser and a fourth branch connected to the evaporator respectively; wherein: a) the first branch , the second branch , the third branch and the fourth branch are provided with a first control valve , a second control valve , a third control valve and a fourth control valve respectively; or b) the pre-lubrication flow path comprises a first common flow path connected to the first branch and the second branch respectively, and a joint of the first branch, the second branch , and the first common flow path is provided with a first three-way valve; the post-lubrication flow path comprises a second common flow path connected to the third branch and the fourth branch respectively, and a joint of the third branch, the fourth branch , and the second common flow path is provided with a second three-way valve; and wherein after flowing from the condenser via the first branch to the compressor for lubrication, a part of refrigerant for lubrication can flow back to the evaporator via the fourth branch ; and wherein after flowing from the evaporator via the second branch to the compressor for lubrication, the part of refrigerant for lubrication can flow back to the condenser via the third branch . wherein the pre-lubrication flow path comprises a first branch connected to the condenser and a second branch connected to the evaporator respectively; and the post-lubrication flow path comprises a third branch connected to the condenser and a fourth branch connected to the evaporator respectively; wherein: a) the first branch , the second branch , the third branch and the fourth branch are provided with a first control valve , a second control valve , a third control valve and a fourth control valve respectively; or b) the pre-lubrication flow path comprises a first common flow path connected to the first branch and the second branch respectively, and a joint of the first branch, the second branch , and the first common flow path is provided with a first three-way valve; the post-lubrication flow path comprises a second common flow path connected to the third branch and the fourth branch respectively, and a joint of the third branch, the fourth branch , and the second common flow path is provided with a second three-way valve; and a) the first branch , the second branch , the third branch and the fourth branch are provided with a first control valve , a second control valve , a third control valve and a fourth control valve respectively; or b) the pre-lubrication flow path comprises a first common flow path connected to the first branch and the second branch respectively, and a joint of the first branch, the second branch , and the first common flow path is provided with a first three-way valve; the post-lubrication flow path comprises a second common flow path connected to the third branch and the fourth branch respectively, and a joint of the third branch, the fourth branch , and the second common flow path is provided with a second three-way valve; and wherein after flowing from the condenser via the first branch to the compressor for lubrication, a part of refrigerant for lubrication can flow back to the evaporator via the fourth branch ; and wherein after flowing from the evaporator via the second branch to the compressor for lubrication, the part of refrigerant for lubrication can flow back to the condenser via the third branch . <EOS>