DHS Opioid Detection Resilience Act of 2020 This bill establishes new requirements related to the detection of illicit narcotics at ports of entry. Specifically, U.S. Customs and Border Protection (CBP) must implement a strategy to ensure chemical screening devices are able to identify narcotics at purity levels equal to or less than 10%, or provide an alternate method for identifying narcotics at lower purity levels. The CBP must also test new chemical screening devices at various purity levels before it commits to their acquisition. Additionally, the Department of Homeland Security must implement a plan for the long-term development of a centralized spectral database for chemical screening devices.